Check Engine Code 55 OBD1

Cotton · #1 07-23-2016, 09:52 PM

Those of you who are on FB have probably seen this, but I'll put this up for those who are on the forum only so I have other opinions on the matter.

I had recently put a rebuilt engine in my 94. It came from a 96. This is obviously going from an OBD1 ECU and wiring harness to a OBD2 engine. There were no issues in getting it to run though.

There has been a lot of work done to my car in getting it to this point and one of the things I had was an exhaust that was in much better shape (ss with a magnaflow compared to my rotted OEM one) that had newer o2 sensors on it. We also replaced the fuel filter, among other things.

We had got the engine to run prior to getting the exhaust on just in case any wiring harness or manifolds needed to be changed as that would have been a lengthy process so getting the exhaust on would be secondary if that needed the work done.

Everything works and is running but we got this check engine light on, even after disconnecting the battery several times:

55-

EGR gas temperature sensor (CAL.)

Abnormal signal from EGR gas temperature sensor.

Any ideas what this could be? Was this from starting the car without the exhaust on and the ECU is still pissed? Is this from new o2 sensors? Other? Any help would be appreciated. Thanks.

fasteract7 · #2 07-24-2016, 07:29 AM

Change the ECU to a non-California model......

theflystyle · #3 07-24-2016, 07:43 AM

I recently went through this. I cleaned all piping and parts as best I could and the issue still remained. I then tested the EGR to see if it would hold a vacuum and it failed. The diaphragm in the EGR housing was torn which prevented it from working properly. I replaced with new OEM and the code went away.

SVX92-97 · #4 07-24-2016, 07:49 AM

Did a similar swap when I put complete drivetrain from my wrecked 96 into my 94 pearlie. Did you swap the OBD I intake onto the 96 engine? If you didnt that would cause a CEL

fasteract7 · #5 07-24-2016, 09:01 AM

I usually get a 34 or 56 code when I need to change out some part of my 92 EGR system. I guess my prior post here was suggesting that a CA emission equiped OBD1/2 SVX has a EGR temp sensor which non CA cars lacked ?? I have no idea where there is a temp sensor on my 92.....EGR solenoid, yes, with wiring there,but I find no other wired connectors. If I'm incorrect, let me know.

Cotton · #6 07-24-2016, 09:02 AM

I tried it this morning and there was no light. I am going to drive it later tonight around the block to see if it comes back on again.

It has a non-CA ECU in it as it was a PA car that was owned only a couple miles from me from the 1st and only owner.

I do have someone that can help me with this with changing what is needed if it comes back and stays on. Stupid question, but considering this is an EGR code would doing a EGR delete get rid of this if it comes back? I know people do it for performance issues on other vehicles but I have read here there is no reason to do it for that on these. In this case though it would not be for performance but rather to clear a code. I guess I'll see if it comes back on.

Cotton · #7 07-24-2016, 06:29 PM

Light came back on during road test.