I just replaced the exhaust from the front cat all the way back on my 97 legacy Brighton with a used exhaust from a 98 outback. It fit perfect and I only payed $150 for it. When I started up the car it was idling rough and the check engine light was on. I thought the light was from th e 02 sensor so I disconnected the battery and it was still there after 10 minutes disconnected.

We checked the wires form the distributor and they were all firing.

I left my friends place and went to the auto parts store to scan the codes. The car ran really rough at idle and stalled as I was turning into the parking lot. I almost hit the sign as I lost my power steering suddenly. It was close.

They scanned the codes. I started the car and drove the 10 minutes home and the car ran perfectly.

So hear are the codes

P0403 - Exhaust Gas Recirculation Circuit Malfunction

po505 Idle control system malfuction

P0443 Evaporative Emission Control System Purge Control Valve Circuit Malfunction

I found this info on the interweb.

 

Any ideas? I have no clue what's happening. Thanks for any help

whenyou replaced the exhaust, what else did you do to the car?

Nothing was done other than the exhaust. We unplugged and replugged in the 02 sensors but nothing more. I believe the 02 code is PO420. I checked the transmission fluid. That's it. ?????????

Edited March 11, 201313 yr by Nbe1210

did you use your original o2 sensors or the ones that came with the exhaust?

I used my front sensor as I had replaced it this past summer with a new one and I think I used the rear from my old exhaust also.

odd

 

no one slipped with a tool and hit any hoses or wiring?

 

P0420 can be caused by many problems, but exhaust leak is one.

Did you have the air filter box off to work from the top on the O2 Sensor connectors?  Check the hoses.

The air filter never came off and the only the three codes i listed above came up on the scanner. No po420. I'll look at the hoses when I have a chance later today. Those plugs on the 02 sensors are a pain to unclip. Maybe something got bumped or knocked loose. Thanks for the thoughts. I'm hoping it drives ok today so I can get to work.

 

Update:  I drove to work this morning and the CEL was on but the car drove fine.  Better than it has in a while in fact.  I  just drove to another building and the CEL is off and all seems fine.  Maybe it was just a computer hiccup??

Edited March 11, 201313 yr by Nbe1210

You might want to check the grounds to your ECM.