Honda Swap VTEC Guide – How To

Honda Swap VTEC Guide – How To


It’s fair to say that over 90% of our Honda swap inquiries we receive here at My Pro Street are about VTEC, how to wire VTEC, and questions about troubleshooting VTEC. To save some time and provide our members with a FAQ on VTEC, this Honda Swap VTEC Guide is born. Part 1 will focus on the SOHC D series as well as the DOHC B series engines from Honda.

Before you plan on swapping in VTEC honda swap however, check here for a guide on removing your Civic engine. This compilation is still a project moving forward, have some information or a correction you’d like to see added to our Honda Swap VTEC Guide? Leave us a message below and let us know!

VTEC How To – OBD1 SOHC Engine in OBD1 Honda Civic

Before we go over all the possible VTEC wiring options for a 1992-1995 Honda Civic or EG, note that all 1992 Honda Civics already have the VTEC solenoid switch run to the shock tower. Because this wire is already in place from your EG ECU harness to the passenger side shock body, all you will need is a Honda Civic 1992-1995 EX or SI engine harness to wire up VTEC.

The following instructions are operating on the assumption that you have a OBDI Civic with the matching OBDI ECU (P28 is recommended)

How To Troubleshoot Your VTEC


Additionally, you can also run the wires from your shock tower to the solenoid and VTEC spool filter to save yourself money and time.

1992-1995 Honda Civic CX – If you are using a P28 ECU, you need to wire both the VTEC solenoid and the pressure switch to your OBDI ECU. If your Honda Civic CX is not using a heated 02 sensor (four wire oxygen sensor) you will need to wire this as well. The engine found in this model is a D15B8 stock, and you will need the appropriate mount kit to complete your Honda swap.

1992-1995 Honda Civic DX and LX – Own a 1992 DX or LX? simply run the VTEC wire from your shock tower to your solenoid and switch to complete the VTEC wiring. You can of course always run wires from your ECU, P28 or P72.

How To Install a Skunk2 VTEC Solenoid

1992-1995 Honda Civic VX – One of our personal favorites for the sheer fact that the VX is the lightest Honda Civic built in this generation, and could get up to 48 mpg before anyone knew what a Prius was. Already wired for VTEC, a OBDI Civic VX is the best donor chassis in this era of Honda Civic for motor swaps. The E-VTEC equipped D15Z1 is quite the funky performer, and you may need to rewire the special 02 sensor to convert from the wideband 02 that came stock, to the standard 4 wire narrowband oxygen sensor.

All 1992-1995 Mini Me Builds – If you are intent on keeping the SOHC alive, and you’re building a Mini-Me SOHC, you will need a VTEC pressure switch so that your P28 ECU knows it’s safe to trigger your VTEC cam lobe. The part number for this VTEC switch can vary, for SOHC VTEC models in the OBDI range the part number is 37250-PNE-G01.


VTEC How To – OBD1 DOHC B Series Engine in OBD1 Honda Civic


When upgrading to a DOHC B series OBDI engine, from the B16A3 all the way up to the B18C1, you’ll want to use a P28 or P72 ECU. Chipping your ECU will allow you to take full advantage of the EEPROM chip in your ECU.

How To Identify your B16 Engine


1992-1995 Honda Civic EX or SI – When upgrading to a B series VTEC engine using this chassis, the VTEC is already wired and ready to rock and roll. If you are using a chipped P28 or have swapped your intake manifold, you may or may not need to wire the knock sensor. The knock sensor for the GSR engine is 30530-PV1-A01, and as stated, you can opt to bypass this by programming your chipping your P28 OBDI ECU.

How To Read Honda Bearings

1992-1995 Honda Civic DX and LX – Removing your D15B7 is easy enough and when you are swapping over to a DOHC B series, you need both the knock sensor as well as the IAB rewired to your ECU. When using a P72 ECU, this means that you must reuse the stock intake manifold. When installing a VTEC pressure switch, the B18C1 Honda part number is 37250-PR3-003, and it can be used across all DOHC engines.

1992-1995 Honda Civic VX – The only thing to change here when swapping a B16, B17, or B18 engine in your VX is to rewire your oxygen sensor to a standard four wire unit. Use our handy How To Guide here to get this rewiring job done in your Honda Civic.

1992-1995 Honda Civic CX – The last entry on our B series Honda Swap VTEC Guide is the CX Civic. Equipped with the D15B8, this car needs the VTEC wiring added to the harness, as well as the knock sensor and IAB wiring. You can alternately opt to use the B series engine harness and add the wires to your shock tower plug for a factory Honda look.

VTEC How To – OBD2 SOHC Engine in OBD1 Honda Civic


If you are not converting from OBD2 to OBD1, you’re going to find quite a few annoyances when moving from OBD2 to an earlier model of Honda Civic. The SOHC VTEC engine from this generation of Civic is known as the D16Y8, and for our Honda Swap VTEC Guide, we’ll be assuming you are using the P28 SI ECU.
How To Service Your Honda Civic Crankshaft Position Sensor
If you are running a P28 Honda Civic SI ECU, your D16y8 will not need to use the knock sensor. Simply zip tie the harness and tuck it out of the way.
1992-1995 Honda Civic DX, LX, CX – You’ll of course need to wire up the VTEC solenoid and pressure switch, as you might expect. This swap can be much easier in fact than a VTEC model, simply because most of the engine components match better. You can simply re-use your non-VTEC distributor, as it will bolt up just fine to your OBDII SOHC Honda swap engine.
If you have a Honda Civic CX or DX you are in luck when it comes to the IAT sensor, just re-use your old intake manifold and you’re good to go. As with the VX and SI example below, to save money and time just reuse your alternator.
How To Change your D16Z6 Timing Belt

1992-1995 Honda Civic EX, VX, and SI – As all these vehicles came equipped with VTEC from the factory, conversion is not very difficult. Because of the obvious OBD generational differences, you will find small things that may hinder your swap from being completed. Your factory OBDI ignition distributor will not bolt up 100% to your OBDII cylinder head, although you can make it work.
Your OBDII intake manifold also will not have provisions for the Air Intake Temperature (IAT) sensor in the runner. You will need to adapt by installing a IAT sensor in the intake piping. You can also choose to use a D16Z6 intake manifold, which will have the right bolt holes in the intake manifold runner for the IAT.
d16 timing marks
How To Change your D16Y8 Timing Belt
Lastly, you will need to rewire your alternator, because the OBDII plug will not bolt up to your OBDI alternator. You can skip this step by just using a D16Z6 alternator to match your vehicle chassis.

VTEC How To – OBD2 DOHC Engine in OBD1 Honda Civic


One of the most well known Honda engine swaps out there, the DOHC B series engine swap rounds out the last of the OBDI Honda Civics on our Honda Swap VTEC Guide. If you are looking for instructions on how to BAR legalize and smog your Honda swap, check our primer here.  For simplicity sake, we’ll be lumping all OBDII B series DOHC Honda engines here, from the B16A2 all the way up to the B18C5.

How To Adjust Valves


1992-1995 Honda Civic EX, VX, and SI – This combination of Honda swap requires that you choose you ECU carefully. Use the factory P72, P30 or P2P ECU and you may have conflicting parts from your OBD2 engine to your OBDI chassis. VTEC is of course already wired into the chassis for these vehicles, but when you are swapping a DOHC engine in, you will need to retain your Z6 injectors for proper install. If you are swapping a DOHC B series into a VX, you should not re-use the VX injectors, you’ll need to go aftermarket or go with EX or SI injectors.

As with the OBDII SOHC examples, you will need to get creative with your intake pipe to mount and install an Air Intake Temperature sensor unless you’re swapping a B16. To use your B series distributor, you’ll need a flying loom that steps you up from OBDI to OBD2A or OBD2B. Use a OBDI B series alternator for the easiest and cleanest install and Honda swap.

How To Install a GSR timing belt


1992-1995 Honda Civic DX and CX – Like the EX, VX and SI examples above, your choice of ECU matters here. Like the EX, VX and SI models, you will need to wire up a IAT solution as well as transfer injectors over. You can also choose to eliminate the crank position sensor if you so wish, as this won’t plug into your OBDI engine harness. If using a P28 ECU to drive your VTEC, bypass the knock sensor or secure the knock sensor harness out of the way.

If you are swapping a motor into your one wire CX Honda Civic, you’ll obviously need the 4 wire oxygen sensor from your choice of engine. This is a big part of our Honda Swap VTEC Guide and huge for you to complete your Honda engine swap.

OBDII P72 ECU Pinouts


VTEC How To – OBD2 SOHC Engine in OBD2 Honda Civic


1996-2000 Honda Civic DX, CX and LX – These non VTEC models will require the standard VTEC input and outputs. Wire up your pressure switch and VTEC solenoid when swapping your D16Y8. If you are keeping the P2P ECU and want to use that in your Honda Swap, it’s important to note that you cannot mix OBD2A and OBD2B harnesses.

Because of this reason, you’ll need to take extra care not to get stuck with the wrong engine harness or dash harness. Also make sure to identify what your Honda VTEC swap is, OBD2A or OBD2B, as all the wiring will be different at the ECU terminals.

You will also need to extend or lengthen your oxygen sensor wire, as this will move it primarily from the front header to the B pipe header outlet.

1996-2000 Honda Civic HX – Much like the VX of the previous generation certain HX models come equipped with Honda’s funky wideband oxygen sensor. Remember that you can use our guide to convert from 7 wire 02 to four wire 02 easily. Much like the DX, CX and LX above, the HX will require you to wire in the VTEC pressure switch and solenoid, and depending on the ECU you are using you may also need the knock sensor IF your Civic HX is a manual.

If the donor Honda Civic HX is an automatic, it will already have the proper knock sensor connector as part of it’s engine harness. When swapping in a D16Y8 it’s also good to note that you won’t need to change the IAT sensor as part of our Honda Swap VTEC Guide.

VTEC How To – OBD2 DOHC B series Engine in OBD2A Honda Civic


1996-2000 Honda Civic EX – Taking the step up from your D16y8 to a DOHC B series isn’t as hard as you might think. You will of course need the VTEC solenoid and pressure switch wiring. If you are retaining the OBD2A P2T or P72 ECU, you will also need to wire in the knock sensor. A chipped P28 can be used here if you wish to bypass the knock sensor, or you can alternately use a P30 ECU.

If you are swapping in a GSR engine, you will need IAB controls unless you are ditching the stock unit for a Type R style or aftermarket manifold (Skunk or BLOX). As with the previous listings, you will need the IAT relocated depending on the intake manifold you are using. If you are sticking with the stock B18C intake manifolds, you can simply convert to the round style IAT and install on the intake manifold runner.

1996-2000 Honda Civic DX, CX and LX – These non VTEC models have quite a laundry list of items you will need to successfully Honda swap your engine and have VTEC working. Obviously you will want the pressure switch and solenoid, but outside of that you will also need to convert the air intake temperature sensor from three wire to a two wire unit.

When removing your D16y7, you’ll find that our Honda Swap VTEC Guide will prove useful in getting your questions answered.

Like the EX above, if you are swapping in a B18C engine and sticking with the stock intake manifold, simply use the GSR IAT. Your secondary 02 sensor will also require lengthening or you may need an 02 adapter.

1996-2000 Honda Civic HX – The only thing that differs in this example from the DOHC to the SOHC is the knock sensor. Make sure to wire yours if you are retaining the stock ECU, or running a P72 or P2T Honda PCM.

VTEC How To – OBD1 Engine in OBD2 Honda Civic

Not smog legal and not exactly a common swap for those living in California or Arizona with stricter emissions laws. When swapping a OBD1 engine into your OBD2 vehicle, you must realize that the basic need are alternator and distributor. You can make the choice to convert from OBD1 backwards if you wish, for that guide click here.

SOHC D16Z6 Engine – You’re best served by running a chipped P28 ECU, but if smog is a real concern you’ll need to;

  1. relocate the air intake temperature sensor (or rewire to OBD1 unit)
  2. Transfer injectors
  3. Cut and splice in D16Y7 alternator plug
  4. Reuse OBDI distributor or simply convert
  5. rewire the idle air control valve.
  6. Eliminate or bypass all OBDII smog equipment

If you are swapping a D16Z6 into a Honda Civic HX, you’ll not only need the above action items but you’ll also need to ditch the crankshaft position sensor, as well as your EVAP purge and the downstream 02 sensor. Yes, your swap won’t pass smog.

If you are swapping this D16Z6 into a Honda Civic EX, the only change from the above items would be that the EGR will also need to be ditched and you will not need to mess with the VTEC solenoid or pressure wires.

That does it for our Honda Swap VTEC Guide, if you have any questions or comments please feel free to leave them below!


  1. I got a 94 Honda Civic DX and i swapped in a b16 but my VTEC isn’t working. both my pressure switch and solenoid are connected. please help

  2. You guys say there’s a seven wire 02 conversion page but the link is broken.. can you provide instructions on how to convert a seven wire Civic VX 02 sensor to the normal four wire 02 my gsr needs

  3. Hey is it possible leaving my original civic dx tranny when trying to swap for a b20 non vtech?. If the swap is possible what all major wiring and changes need to be made to my civic

  4. hey guys i have been reading through here and although i found alot of useful info i didnt find an answer to my problem. i have been building my engine for over a year now and have finally made it to start up. so heres what ive got a fully built b20z2 block with a pr3-2 head cast in 1992. and its paired with a gsr type R lsd tranny with 4.4 final drive. im using a skunk 2 intake manifold paired with a 70mm TB. all sitting in a 94 cx shell runnining a p28 with hondata s300.idk what my harness came from originally but i do know there are some wire that have been cut and now route nowhere as others have been soldered new color codes onto the last 5 inches of them. right now my biggest problem is my IAT sensor mounted to the intake manifold is showing in real time 282f which is way off cause the car is cold. i also checked the voltage from the plug and my red wire shows 12.97 volts and the yellow wire with black stripe shows 11.07. now i dont do very good with wiring but from what i can find the red wire is supposed to have 5 volts and the yellow none. i believe this is causing my car to run super rich (9.7)FAR at idle…. id like to just buy another harness that will just plug in and not have to be modified . any help would be very appreciated

    • Hi Brad, thanks for reading..

      quick question when you say IAT sensor, this is a 2 wire sensor not a 3 wire one? We can add or whip up something for you to reference and test your intake air temperature sensor, but we want to make sure you have the right sensor in mind.

      You should not have power at both wires is what we are getting at, and that’s the reason for the problem. If you give us a little more information we might be able to tell you if its a shared ground or an issue with your main relay wiring.

      let us know and maybe we can help you out.

      • Actually I searched for a few hours last night and figured out that I have my evap solenoid and iat sensor plugs reversed. I fixed that and I’m now getting an a curate reading but now I’m trying to figure out why I’m still running super rich. I have 365cc injectors and an adjustable fuel pressure regulator but idk what I should have my fuel pressure at. Now idk much about tuning so idk if I’m supposed to dial the Injectors down or reduce the pressure or perhaps both.

  5. I have a 97 civic ex. I am looking to build a motor for it but i need to know which motor Would work best. It seems a b18c3 with a turbo would work. Will it fit?

  6. Hello I have a 16z6 engien on my ex civic model if I want to swap to a 94 gsr is it just plug and play or do I need to re wired anything I’ll be using a chipped p28. I’m pretty confuse ? so please help me

    • Hi Dennis, if you have a D16Z6 engine in your EX, you will need some slight changes to the engine harness to make it work on a VTEC DOHC GSR engine, but your chipped Honda P28 ECU is a great start! Thanks for commenting! It sounds like a great project! let us know how it turns out!

    • Hi sir! what ECU are you running? A p28? wiring up the VTEC is fairly simple, especially on that Honda ECU. Let us know and we can help!

  7. I have a 1999 civic dx 1.6l an id like to put a vetc in it I can get a 2.0vtec out of a 95 accord ex but didn’t know if it will work any info will be a big help

    • Hi Tylor, this Honda engine swap will work, but it’s best to use a motor mount set that’s designed for your F series. Luckily for you there are many new mount kits that make this swap extremely easy!

      Sounds like a great project! let us know how it turns out!

  8. What will I have to do for a D17A1 motor from a 2002 civic lx to work in a 2000 civic ex that had the D16Y8 without having any problems?

    • Hi Kacey, this swap isn’t very common but it’s growing in popularity! We would suggest a motor mount kit that’s suited for your EK to swap the new SOHC D series engine into. Other than that you’ll need a 2001+ Civic ECU to complete your swap! Sounds like an interesting engine swap! Let us know how it turns out!

    • Hi KC! Thanks for reading!

      This swap isn’t common so you would definitely win points for originality! As it’s an OBD0 it’s probably best to just ditch the complete engine harness and swap in a OBDI H22 from a Prelude! Thanks for commenting! Sounds like a great swap, let us know how it turns out!

  9. I have a 2001 Honda Civic LX Sedan and I want to swap out the engine for a more powerful one. I have been looking all over the place as to which route I should go since I do not know which engine would fit, but cannot find much information for my car. What engine would be best for more power? And what would I need to change in order for the engine to fit in my chassis?

  10. HI guys ive got a 95 prelude sr with a h22a4 engine swap ive swapped to obd1 distributer and h22a1 injectors i had a cel 22 so i bypassed the oil pressure sensor at the ecu (p13 ecu) still have cel 22 the car splutters in the lower rpm range and i have no vtec redlines at 6500rpm am i missing some wiring? its driving me nuts! Thanks

    • Hi Glen, thanks for reading!

      When you say you bypassed your VTEC oil pressure switch, how did you do this? You are sure it’s a CEL 22? If your OBDI H series is having a VTEC pressure switch issue, try replacing it.

      If you’ve bypassed it by jumping it, that probably won’t resolve the issue.. If you’ve replaced the oil pressure switch and the CEL is still there, try checking for continuity between your P13 ECU and the pressure switch.

      Let us know how it turns out! Thanks for commenting!

  11. hey thanks for the reply i changed the pressure switch already didnt make any difference and i still had the cel. i bypassed it at the ecu by combining the vtec solenoid and pressure switch at the ecu and running both wires into A4 i bought the car while it was running on a p14 i installed the p13 ecu obd1 injectors and dizzy connected the solenoid and pressure switch via the two unused wires on my passenger wheel arch in the engine bay one blue one green and yellow im sure i connected these correctly and ran the pressure switch ground wire to the body. at first i had no rpm tach however i reground the wire and resolved this. how can i check for continuity? and as im still using the obd1 non vtec harness i was wondering if i had to rewire anything else at the ecu? thanks!

    • Hrm.. that’s weird.. yeah if you have already replaced the pressure switch I would check for continuity between the pressure switch and A4 as well as your pressure switch wire.

      Check this guide here for some other reasons why your VTEC isn’t kicking in.

      If you have continuity between these wires, I would try replacing your ECU. Are you sure there are no other stored codes? If you’ve jumpered it correctly as you state, the car shouldn’t be struggling like it is.

      Check for continuity and let us know, I’m sure you can track down the source of your issue.

  12. Hello Prostreet!!! I’m about to swap out my B20v motor out of my 96 Rs Integra to a 94 Civic vx. I was reading the part about the swap on your article but I still need a few questions about it. So can I jus plug & play the VX harness for the swap??? & also it says to convert the o2 Sensor to 4 wire. Is the o2 sensor wires still Necessary if the Tuner deleted on crome?? Cuz I’m on Aem wide band.. Pls let me know if there is anything else I should know about for the swap. Thanks!

  13. Hi prostreet I have a 1986 Honda prelude 2.0 si and the motor says bt on it and I just bought a donor motor and the other motor says it’s an a20a5 or a3 not sure if the swap is going to work it’s from a accord 1989

  14. Hi I’ve got a 96 civic coupe 1.6 and I want to put a new engine in as it’s nakerd and I want somthing more fun.what fits in,idealy somthing with good aceleration not too worried about max speed atall. Thanks alot

  15. I have a 1988 civic DX hatchback with the d15b2. I found a d17a2 for a really good price. I have heard that D series motors all swap but can’t find the info I need to do the swap or if it’s even possible. I know it’s not a K series swap but it is going from 90hp to 127hp and on a budget. Lol. Just looking for any info to help me with the engine swap.

    • Hi Keith, thanks for reading.

      the D17A2 is a good swap, but it’s not very common because there’s a lot of differences that could prove difficult. As far as the mounts go I would choose an aftermarket mount kit, which lets you bolt in the motor, which is the basics.

      The next thing to check is the alternator and air conditioning layout, as you’ll more than likely have to find a way to adapt your existing setup in your Civic EK.

  16. I have a 99 civic dx sedan automatic and was wondering what the best swap possible is to turn it into a beast? Mind you i live in CA. 🙁

  17. I got a 96 civic HX motor and transmission 5 speed D16y8 , and I want to put it in my 98 civic LX . Can I use my stock LX harness ? And what is it I gotta do to it, or can I use the 98 HX or EX harness???

    • Hi Steven, thanks for commenting!

      I would stick with your LX harness and just add what you need to make it work. There isn’t much really. You should check the alternator plug to ensure that bolts up however.

      Best of luck to you and let us know how it turns out. thanks!

  18. Hello,
    Recently purchased a 1998 civic hx 5 speed manual. CEL Was on for stated manifold leak. But may be more than that and trying to solve the issue.
    I have figured out its a d16y5 block with a y8 head and still has the hx civic ecu.
    Car runs very well but only issue I’m trying to figure out is why VTEC isn’t engaging.
    Appears he has converted the o2 sensor I think? (Primary o2 has 4 wires, secondary has 3 wires)
    So my question is any suggestions on what actions I need to take to get VTEC working?
    (Has a vtec solenoid, not sure if correct one though.


  19. Hi, new to honda father recently purchased
    Honda DX 1.4 Auto (UK car) keen to install
    B series vtec conversion what would be best
    option with minimal loom cutting, father has
    Access to similar year left hand drive CRX could he utilise pedal box on this vehicle?

  20. I have an all stock 1998 Honda civic dx with the d16y7 engine and manual transmission. Due to the original engine blowing a head gasket I want to swap in a d16z6 engine I have. The original engine is already out and I am wondering what wiring modifications I need to do in order to make this swap work?

    • Hi Dustin, are you going from OBDII to OBDII? If so you shouldn’t have to change much just to get the engine working. Have you checked the VTEC guides on adding the wires you need?

  21. I have a 1988 Prelude that has issues that cannot be repaired due to the fact that Honda no longer manufactures the parts. So it is a 2.0 SI 4WS and I have an opportunity to purchase a 1998 Vtech engine with low mileage, will this engine fit in my 1988 Prelude?

    • Hi Daniel, unfortunately this H22a4 VTEC Honda engine swap from the 1998 Prelude isn’t a direct bolt in affair for your 1988 Prelude. You may want to look into junkyard replacement engines if yours has gone out. Hope this helps and thanks for commenting!