could bad O2 sensors cause a rich code?

[RysRed96GT]

i've gotten a CEL saying i'm rich in bank 2 only. only guess is this is because i removed bank 1's sensor before pulling the heads. so maybe some of the coolant and other gunk got down bank 2 and onto that sensor.


could a faulty sensor or one that's had crap like coolant or cleaner go through it cause it to think it's running rich or throw a bad code?

i dont see how it can be rich on one side though. i look at the tailpipes and i see equal amounts of carbon, though very little on the tips. any ideas?!

 

[03gtmustang]

Yes, a bad 02 sensor could throw a code.

 

[RysRed96GT]

Yes, a bad 02 sensor could throw a code.

i know it can throw a code, but would the code be saying the car's running rich when it really isnt? my code i got was a p0175 from bank 2 only.

 

[BuffaloZone]

i know it can throw a code, but would the code be saying the car's running rich when it really isnt? my code i got was a p0175 from bank 2 only.

I've been seeing a lot of catalyst failures lately - and usually on "Bank 2" for some reason. Failures mainly on trucks, but the catalytic converters seem to look pretty much the same in style and size and many converters are rated more on vehicle weight instead of engine size. Most bad ones that I've seen are the newer small design. If you can't actually scan the O2 pattern, you can check the exhaust temperature to see if the catalyst is functioning. With exhaust fully warmed up, the exit temperature right behind the converter should be about 100 degrees hotter than the inlet temperature (showing that the catalyst is still working) - if the outlet temp is near or same to inlet, you have a dead converter. I use an Autopro Infrared Non-Contact Thermometer.

If the converter still seems to be working, then you could have a bad sensor.

 

[RysRed96GT]

ok, i just pulled the sensor. it had tons of white crap on it, like it was frosted. which was not on the bank 1 sensor. i think it's just fried from coolant.

im assuming it's time for a new sensor then. how much are they?

 

[MyEarsHurt]

They are pretty cheap, I think I replaced mine for like under $40.

 

[RysRed96GT]

replaced both? what brand were there? where'd you get them, autozone/advance?

 

[PiranhaGT]

O2 Sensors are NOT cheep! At Advance Auto Parts they were $60 each!

 

[RysRed96GT]

O2 Sensors are NOT cheep! At Advance Auto Parts they were $60 each!

dumb question but could i replace just one? or do i have to replace both?

 

[DELOS02GT]

You can just replace one, but you should do both. I have a questiuon for you....the check eng. light is on in my car too. I have the Diablo Pred. and I turned the rear O2's off, but it says the code is on bank 2 sensor 1. What O2 is that?

 

[RysRed96GT]

You can just replace one, but you should do both. I have a questiuon for you....the check eng. light is on in my car too. I have the Diablo Pred. and I turned the rear O2's off, but it says the code is on bank 2 sensor 1. What O2 is that?

not sure, but how many sensors are there? i thought there were only 1 per side?

 

[DELOS02GT]

That's right....yours is diff. than mine. I have 4 O2's...you only have 2.

 

[jstreet0204]

You can just replace one, but you should do both. I have a questiuon for you....the check eng. light is on in my car too. I have the Diablo Pred. and I turned the rear O2's off, but it says the code is on bank 2 sensor 1. What O2 is that?

Bank 2 sensor 1 is the driver side front O2.

 

[zgarske1038]

bad o2's can cause the car to run rich i dont know about faking it though

 

[03gtmustang]

I have a question for you all. Before I installed my 75mm t/b and plenum I had a 85mm maf on my car. With just the 85mm maf the car was running fine, no rich or lean codes were being throw. After I installed the plenum and t/b my car threw a lean code. So I decided to take off the MAF. Well the car is still running lean with just the plenum and t/b, I even put my silencer back on. Could this be because I need a new 02 sensor (I havent checked them yet), or could it be because I need a new MAF sensor, or do I just need a tune with the new mods? The plenum and t.b have been on the car for awhile now so it has had time to adjust to the new mods, and yes I did reset the computer already.

 

[DELOS02GT]

Bank 2 sensor 1 is the driver side front O2.

Thanks!!!!

 

[03gtmustang]

I just pulled my codes with my superchip, I got P0174- Lean in bank 2, and P0171- Lean in bank 1 can someone tell me which 02 sensors these are so I can pull them out and check them. Im guessing my car is actually running lean since its both the sensors as apposed to just 1?