P2A00 code, HELP
 

Hey guys, I have a P2A00(A/F bank 1 performance) code. I replaced the sensor with a Denso sensor, cleared the code and the code came back 2 days later. Any ideas?

F.Y.I I bought the car with Stillen Cat backs and Stillen Gen 3 intakes on it already

You are running two different branded O2 sensors?

no test pipes/hfc's?

There's a lot of info on this code. Exhaust leak and dirty MAF's seem to be the top two problems. There's more that can cause it.

Have you confirmed this.

note the question mark- I was asking the OP.

No test pipes or hfc and I just replaced the stock o2 with a Denso o2 on the passanger side

I know that smart guy. Im confirming this with the op to make sure he has looked. Don't flatter yourself.

Aftermarket sensors may read differently from the stock ones. If you are running mismatched O2 sensors, it is very possible and likely to throw a code because your ECU is seeing a voltage variance. I would either replace your other O2 sensor with a Denso, or replace the Denso with a stock one. Just make sure they match.

Ok, tommorow at my shop I will use the scan tool to read voltages of both o2 sensors and get back to you guys I will also clean my MAF sensor. Thanks for the feedback to this point

Checked with my scan tool found bank 1 fuel percentages at 22 and bank 2 fuel percentages at 7 thinkong I need a MAF in bank 1 so I'm swaping sensors and rechecking

Stupid question, but have you cleaned the MAFs yet? It's far cheaper than the alternatives.

I think he means he is going to swap them and retest to see if that confirms a bad or dirty MAF.

Might as well hit them with maf cleaner while they're out. Can't hurt.