Contour Enthusiasts Group Archives Forums Modifications Duratec Maintenance O2 sensor lean, Bank 1, 2nd sensor

I hope I didn't post this yet.

So I had Autozone scan my 96 Zetec. He said the code he read (CEL is on) O2 sensor lean, Bank 1, 2nd sensor. 2 questions.

Is there a code number for that? He punched in the year, make and model into his scan tool, so it may have just given him the text pertaining to the code.

Do you think just changing that sensor with a new one would take care of the CEL problems?

Firstly the lower aka second sensor CAN NOT throw a lean code. It has to be an upper sensor.

I do have a generic OBD II code listing, don't know how it pertains to the Countour, but code P0137 says "O2 circuitm low voltage (cylinder bank no 1, sensor no 2)". Might that be what he meant? I though low voltage would be a lean condition for an O2 sensor. I too though it odd about the sensor after the cat converter reading lean. But then it should be, shouldn't it. The cat converter burns the engines unburned gasses, does it not?

I hate to dump 60 bux for that O2 sensor if my milage would not improve AND perhaps I might still have the CEL on.

All this electronic crap. What have we gained? A Contour that gets 24mpg? My Road Runner, when I had the 383 (V8)converted and running on 4 cyl, got that on the hyway. No wonder I gave up auto wrenchin, unless absolutely necesisary. I am very much into computers and electronics but this automtoive electronic thing controls us as much as our vehicals.

Dang it. I'm in Duratech maint section. I should have posted in Zetec maint.

IF there is a circuit malfunction it does NOT mean lean. It means the O2 is fried. And seeing as it it Bank 1 Sensor 2, it's indeed the lower one that's done.

don't assume that O2 codes mean lean/rich or worn out.

IT's best to post the code and let us OG's decipher it than come to a guessed conclusion like you did.

I would swap out the lower O2, but I would buy it (234-4609) from sparkplugs.com for $45!

http://sparkplugs.com/results_app.asp?AAIA=1362226&mfid=3

I don't remember assuming anything. I asked what the code number was for the statment the Autozone guy told me. "Bank 1, sensor 2 lean".

That's why you NEVER trust the dufus at Autozone. Just get the CODE not his stupid advice. They ALWAYS tell you "Yep you need a new O2 sensor!" Most of the time it's BS, but at least he sells you a $60 part. In this case it isn't lean BUT your O@ is indeed on the fritz.

So, I went to AutoZone due to suggestions different ones on this board have made, had my car scanned, now I should not beleive them? (Never been in an AZ before yesterday.)I did have a blown HG, O2 would have got wet from that. Batt was disconnected, but the CEL came back on shortly after I restarted the engine after HG replacement.

Perhaps I should disconnet the batt again to clear the CEL and stored info to see if it comes back again. After coming back from AZ, I did check and clean in and around the connections for that sensor. I wonder if that CEL would normally turn itself back off W/O having to clear the code(s) out, if the problem goes away on it's own or from something one might have taken care of?

What might be the correct voltage that O2 sensor would be putting out if it were functioning properly? Maybe I could artificially induce that voltage, after clearing the CEL codes and see if the CEL comes back with another code if it comes back on.

Did I mention how much I hate this new technology junk? (Not my Contour, I like that. All these sensors and devices that cause CELs and the time and expense to remedy. Jeepers! I used to rebuild and install engines faster than one can take care of CEL problems. Often cheaper too!