Tarnold019

Hey guys, I have an automatic 97 civic ex and the motor is knocking, I bought a 99 automatic civic ex for cheap with intentions of swapping the motor to the 97 shell. I'm running into the problem where the 97 is OBD2A and the 99 is OBD2B obviously. Could I just drop the OBD2B motor in the 97 shell and call it good or do I need to make some changes and actually run the OBD2A ECU and harness? I'm not looking for which is better, if it were my car I'd run OBD1 conversion and do a manual swap. Please help, I need to know what problems I'll run into before I drop the motor in. Thanks feel free to ask questions!

Deetz

The engines are the same!! They even use the same distributor. Swap the engine in the newer car, use the original harness of the newer car, everything will plug in fine

HondaPartsHero

The distributor won't plug and play, reuse your cars original one. Also the 96-98 02 sensor is in front of the engine and the 99-00 is before the cat, just reuse your exhaust manifold for ease of install. The rest should be plug and play.

Deetz

What's different about the obd2 distributors? i have both sitting in my garage, never really looked at them, thought they are the same?

I know that obd1 distirbutors are also the same except have two plugs instead of one, and can be repinned using the exact same colors, takes ten mins to do, as i have done it on b series

-update- i went and checked those dizzy's, both one plug, but different style, you are correct. Easiest to just reuse the original one with the car it's being swapped into

Ej8 d16

iTrader: (2)

Intake manifolds are also different, if you have it, 99-00 have some sort of air injection. You have to reuse your obd2a intake manifold.

Reuse your engine harness, distributor, exhaust manifold and intake manifold and your good.

Tarnold019

My main problem that I can see is, on the OBD2A motor harness there is an extra plug on the drivers side goin into the cab. I have the complete 2B swap, harness, ecu everything. Can I just put it in the 2A shell and be fine? I'll take pictures of the plug I'm talking about tomorrow, just not sure what it would go to. Thanks for the replies everyone

Deetz

I'm going the opposite direction as you. I'm putting in a complete 1997 obd2A engine with 50k original into my 2000 civic sedan with a blow engine. All I'm doing for the swap beside a couple refresh parts is swap over the engine harness, dizzy, and intake manifold. The engine itself is the same, so should be a straight forward swap, and plug & play

HondaPartsHero

Can't use the OBD2B engine harness in your OBD2A car, it's not compatible with your cabin harness.


No don't swap intake manifolds, yes they differ but only mechanically not electrically and the FIA system he's talking about is self contained so it won't interfere with your OBD2A system.

As for the distributors here's some pics

Tarnold019

Even if I use the obd2b harness and ECU? I know that the ECU plugs are different but if I just use the obd2b ecu and harness in the obd2a car how is it not compatible? The only thing I see different is on the driver side where the engine harness plugs in, going into the firewall, is on the 2a car there is 2 plugs and on the 2b car there is only one but is the same as on of the 2 on the 2a car.. I'll add pics in a sec

HondaPartsHero

No you can't sorry

Tarnold019

OBD2A driver side plugs (also look at pins)

Tarnold019

OBD2B driver side plug

Tarnold019

If I cant, I need to swap the harness and ecu over and the distributor? Anything else?

HondaPartsHero

Just use the 97 engine harness and distributor And ECU.