02 Sensor Question
 

Hey guys,

It seems that my struggles as of late with the CEL and t/c light issues are likely due to a bad 02 sensor. I'm guessing the rear one because I think I blew it out when I ran my header/dp combo. I think the extra flow and/or the sensor being in the cat blew it out and is no longer working properly. It's throwing mad CEL's which are not able to be "scanned" out and my dealer had it on their machine and couldn't reset the computer either. So I'm figuring it's the 02.

So my question is simple. How much is a new 02 for a Cobalt? I'm guessing they're the same sensors across the board for all models? Can you get them at a general parts store or do you have to get them through GM? I can install it myself and save 70 bucks. Hopefully it's like 50 each. But we'll see. Also, are they both the same one, or is there a different sensor for the front than the back?

Please let me know so I can get this fixed soon. If it's like 150 each, I'll just get HPT. But we'll see. Thanks in advance.

EDIT: See post 11 for codes from scanner.

You can get them through any auto parts store. Autozone.com has yours listed for about 70-90 dollars. (for the one after the cat. 109 for the one before.)

Goddamn. Does it sound like a bad sensor? Any way to test it without buying one..?

If the guy who was scanning ur car would kno if it had a bad o2 u can llook at the voltage a response rate take it to a shop with a good driveability tech

Whats the actual code the computer is throwing?

The second O2 sensor is only to measure for cat efficiency. It should not cause any major issues except a CEL for cat efficiency. If the first O2 sensor goes out that is when you can get all kinds of problems.

If you can get a list of CELs that the car is throwing it would help alot.

Yeah, I'll go ahead over to the parts store and run a scan and write down all of the codes. The "cat inefficiency" was popping up when I had the ZZP header/dp combo on, but it's even still up whenever I went back to the stock combo and had the dealer flash my car.. lol I'll get that list up tomorrow hopefully. Thanks!!

If the first O2 sensor fails it will also through a cat efficiency code.

The cat efficiency code is thrown if there is a mismatch between the expected readings between O2-1 and O2-2. if either sensor is malfunctioning it will cause the comparison betweent he two to be off.

I have a narrowband AFR in my car. I hooked it up the "easy way" and spliced it into where the computer wires are. I'm not sure which sensor that gauge is reading from, but that one seems to be reading fine..

Basically what is happening is the cars CEL and t/c light is on. The car just generally seems to be driving "off". It's shifting really hard, the RPM's drop low sometimes, etc.

This all started once the CEL and t/c light came on. And I'm guessing it's sensor related because it started exactly when I installed the cat onto my ZZP header/dp. I got the ZZP header/dp used from a local guy and installed it. There was no cat, so it obviously threw lots of CEL's. But at that time there was no t/c light or shifting issue. It was just really REALLY loud. I then went over and got a cat thrown on. It was then, exactly as soon as I got the cat thrown on, that the t/c light came on and it started shifting hard. It's been going ever since. I've had the car scanned and even dealer flashed to no avail. It only went off for a few days after the first dealer flash, but then came back on. Thus why I'm assuming it's sensor related.

Any ideas? I'm gonna go over and get the car scanned here in a few hours and i'll post the results. Anything I should be looking for?

Whenever they put the cat on they may have damaged something. The CELs should tell us more about what is really going on.

That's what I'm guessing. Gonna go up soon. Will post the results. Thanks!

CODES:

P0030

P0036

P0053

P0054

P0102

P0443

Any ideas..??

Anyoneeeee..??

https://www.cobaltss.net/forums/showthread.php?t=93655 have a look at that, has 3 of the codes you listed and a fix for them

p0053- HO2S Heater Resistance Sensor 1 ECM
P0054- HO2S Heater Resistance Sensor 2 ECM
p0443- evap purge controll valve malfunction

the p0053 could very well be fixed with the link i posted above. the evap problem, well, id say fix the others first and see if that one comes back.

CODES:

P0030 - HO2S Heater Control Circuit Sensor 1 ECM, PCM

P0036 - HO2S Heater Control Circuit Sensor 2 ECM, PCM

P0053 - HO2S Heater Resistance Sensor 1 ECM

P0054 - HO2S Heater Resistance Sensor 2 ECM

P0102 - Mass Air Flow (MAF) Sensor Circuit Low Frequency ECM, PCM

P0443 - Evaporative Emission (EVAP) Purge Solenoid Control Circuit ECM, PCM


I would definately check for a short. It is possible that the O2 sensor wires were damaged when you were working on the exhaust. It is also possible that you knocked something off of your "narrowband AFR" when you were working on it. Time to start tracing wires.

So, without looking at the links (on phone) it seems like it's not so much the sensors that are bad, but the wiring perhaps? Think that it'll likely be a simple-ish fix? Cheap too? I don't mind splicing in new wiring into trouble zones, I just want to know that that is the likely fix. Sound about that way?

Also, why are these "heater" issues? Or is that another term for something? I was expecting 02 issues..

Thanks for all the help so far though guys!!

The O2 sensors have heaters in them so the O2 can reach its "operating" tempurature faster. It definately looks like a wire was pinched, or damaged somewhere and it is shorting out. At least, that would be my first guess.

Yeah i think i'm having the same problem because where i have a auto 2.4 my 02 sensor is really close to my tranny and now i have a cell. i 'm soo fucking pissed off right now i guess i might have to take this off and go back to stock.

So likely it's not a bad sensor, just a wire for the sensor? Thus a simple "cut n splice" will solve the problem?

See, I tried to check out all of my fuses before, and even swapped a few with others. The one time the CEL went off, but then came right back on the next time I turned the car on. Would that be a fuse? I'd assume that if the CEL came on randomly while driving that it'd then be a short.. Correct? Since I don't have a scanner, I'll try to replace the suggested fuse and then do a hard reset with the battery. If that doesn't work, I'll look for some shorts. Would that simply be bare wire touching something else? Does anyone happen to know the easiest way to reach the wiring loom that comes off of your BCM? The loom is kinda at the bottom of the engine bay. It's what I hooked my Shift Plus into back in the day. I've since removed it and I want to re-patch the wiring.. Any ideas?? Thanks!

You've got to be fucking kidding me. lol. It was the fuse all along. I check them all - but that one. lol Ridiculous. But thanks for the help!! Although it would've been more more helpful to know this months back.. lol

LOL. Probably accidently shorted the wire when doing the install.

Which fuse man? I'm having the same problem