Convert 95 Corolla to OBD2 by replacing engine.

[Inntel]

Hello,

I have a 1995 Corolla DX with the 7AFE engine and the 4 speed automatic transmission. I need to replace the engine and I was thinking of purchasing a 1996 7AFE engine with the additional parts needed to convert the car to OBD2. So far I have found the following differences:

Engine Control Computer
EGR Valve
EGR Temperature Sensor (None on 95)
Idle Air Control Valve

I assume also that the engine wiring harness may be different, as well as requiring the OBD2 connector to ECM harness, which may or may not be attached to other stuff in the cabin. Interestingly there appears to be a knockout under the steering column just the right size for an OBD2 connector.

I'm not sure but there appears to be an additional oxygen sensor somewhere, unless that is only for the California models.

I am wondering if I'm on the right track, or if I'm missing something. I am planning to get a complete engine and transmission with the wiring harness already attached and simply drop it in.

Daniel G.

[TheNightWolf]

Originally Posted by Inntel

Hello,

I have a 1995 Corolla DX with the 7AFE engine and the 4 speed automatic transmission. I need to replace the engine and I was thinking of purchasing a 1996 7AFE engine with the additional parts needed to convert the car to OBD2. So far I have found the following differences:

Engine Control Computer
EGR Valve
EGR Temperature Sensor (None on 95)
Idle Air Control Valve

I assume also that the engine wiring harness may be different, as well as requiring the OBD2 connector to ECM harness, which may or may not be attached to other stuff in the cabin. Interestingly there appears to be a knockout under the steering wheel just the right size for an OBD2 connector.

I'm not sure but there appears to be an additional oxygen sensor somewhere, unless that is only for the California models.

I am wondering if I'm on the right track, or if I'm missing something. I am planning to get a complete engine and transmission with the wiring harness already attached and simply drop it in.

Daniel G.

The additional o2 is on the exhaust.

So probably a new exhaust is needed too..

Just wondering, why swap to obd2?

[Inntel]

I travel a lot and I've come to rely on Advance and Autozone providing free scans but they only support OBD2. I also want to get a scanner and the OBD2 ones are much cheaper and there's a bigger variety to choose from. I decided since I was spending the money to replace the engine and transmission that the additional cost to get the needed parts would be worth it.

Originally Posted by TheNightWolf

The additional o2 is on the exhaust.

So probably a new exhaust is needed too..

Just wondering, why swap to obd2?

[Bitter]

You'll need to pull the dash to un-wrap and replace the harness.

[ganda1f]

Originally Posted by Inntel

I travel a lot and I've come to rely on Advance and Autozone providing free scans but they only support OBD2.

With OBD1 you do not even need a scanner to get the codes. It feels like doing a LOT of work (pulling the dash) only to have more stuff that can go bananas. EGR getting clogged for instance. Personally I would stick with OBD1. Unless there just is no choice, like regulations.

[Bitter]

No kidding, paper clip > relying on a place that's open 9-5 and usually crewed by idiots looking to sell crap.

[kennydang91]

I would just save the trouble and buy a scanner that reads both OBD1 and OBD II.

Amazon

Amazon

[marsala4]

I am in the middle of doing a 93 into a 97 swap, trust me, you do not want to go the other way, You will come out way ahead if you stay with the OBD1 engine.

I wish I would have just bought an OBD2 engine to put in. So, why didn't I, because I already had an engine, didn't make sense to buy another. But, knowing what I know now, I would have done it different.