Contour Enthusiasts Group Archives Forums General Troubleshooting CEL 172 + 176 ?'s

So far I've changed plugs, did a UIM/LIM cleaning. The gaskets looked like they had been leaking. I figured I had fixed it as the wife reported no CEL for almost a week. Then while driving up a relatively steep hill for a mile or so the CEL came back.

I've done some searhing and found where someone had suggested a faulty fuel pump. I will check the pressure tonight when I get home but I wandered if anyone else had any ideas? I had bought an O2 sensor but never installed it with the IM gaskets looking the way they did, I returned it. I am have doubts about 2 bad O2 sensors at the same time. I also hear a slight whine from what sounds like behind the rear seat area when you first start the car. Almost like a struggling fuel pump. I don't have a problem changing the pump. But I don't want to go through that hassle and find something else is causing it the trouble.

TIA,

Tim

Any one?

Codes 172 and 176 indicate that the system is reading the exhaust as lean while it has reached its correction limit for enrichment.

Did you check your fuel pressure?

Have you inspected the PCV hose for a vacuum leak? Any other vacuum leaks?

Does your oil give evidence of Fuel contamination?

Have you run the CBT (Cylinder Balance Test)?

Steve

I've had O2 codes before and each time it was something else... My CEL light has been blinking for quite sometime and it was always something else.

In the last year and a bit I was getting O2lean codes, egr codes, IMRC codes....

I've cleaned my EGR passages at the TB
Cleaned the UIM and LIM which in retrospect was not nescessary
Replace the IMRC vacuum solenoid (as it was toast)
Repaired a small vacuum leak
Just replaced the EGR pressure sensor which sits beside the IMRC solenoid...

I think when your EGR pressure sensor starts a slow death it can throw some erroneous codes your way.

To date, I have way better mileage, No lean codes, better yet, no CEL's at all... and I've never replaced my O2 sensors....

Start with cheap fixes and move your way up.