Manager Forum

We had a '96 Acura brought to us that would not set 3 monitors (O2, CAT and EGR).

We saw that it had multiple problems from the get go. Coolant temp would max only at about 160, so we replaced the thermostat to make sure it could go into closed loop and run the other monitor tests. We also were able to watch the O2 signals and see how lazy they were. We replaced both front O2s with OE units.

Now the car gets up to temperature beautifully, all O2s are switching beautifully, but it will STILL not set the monitors for O2, CAT or EGR.

Anyone come across this problem?

Dan

Never seen it myself, but I've heard of PCM's causing this. Also, maybe the heater circuit is open or high, causing the PCM not to pass the O2 monitor. It wouldn't run Cat until O2 passed I think. Just a thought.

Make sure that it doesn't have an aftermarket radio where they have blown the backup fuse for the radio/computer backup. I have seen this on the Civics before.