My 07 2.2 had been throwing a P0420 code, so I just changed the Cat, which took about 15 minutes. I cleared the codes and let car run for about half an hour in the driveway and no codes. I went to drive home and now it's throwing a P2A01 code (O2 Sensor Circuit Range/Performance Bank1/Sensor2). Could I have damaged that sensor when I took it off the old cat? I used a 1/2" Impact gun just to loosen it.

I also found a Walker Resonator setup for $50 bucks at PartsGeek.com. I figured I could changed the whole thing. Would you change the muffler on an 07 with 150K on the clock if it was only 50 Bucks?

 

the O2 sensor is most likely damaged internally! I changed the muffler out to a Magnaflow I purchased from another member on the site!

 

Sound like you need to replace the down stream 02 sensor however I would recommend changing both 02 sensors.

Sometimes a new fast working downstream sensor working with a old slow working up stream sensor will sometimes throw a false cat convertor efficacy code.

Don't forget to at least visually check the 02 wiring for damage.

 

Don't use impact tools on sensitive electronic equipment. Even dropping an O2 sensor can damage it.

I fixed my P0420 by replacing the flange gasket, downstream O2 sensor and a SeaFoam treatment. A lot cheaper than a new cat.

 

OK, so I just replaced both O2 sensors and cleared the codes. Rode the car about a week with no CEL on. Now it just came on when I started the car this morning. P0054. which is for Bank 1, Sensor 2, Heater resistance. I never got this code before, what would cause this code to get triggered?

 

On a side note, the last time I removes the Air Filter assembly, the "Intake Duct" fell apart in my hand. I am running the engine without it. I still have the Air filter assembly in place, but the Intake duct which goes to wheel well and connects to back of air filter assembly is missing.

I don't think that would have anything to do with it, but.

 

Wrap it with metallic duct tape. Not Duck tape. Turns out the tube is important.

 

Did you for certain get the correct sensor? There is much confusion by parts sellers. Did the color of the connectors match? I assUme you did not get generic splice-in sensors. Could be a simple wire or connector.

Some of those codes need multiple occurrences in order to light up the CEL. And I don't think the heater test runs every time. Clearing the codes causes the emissions testing to start all over, and some of them take a long time to get started.

And, as I was always try to get across: just because a code description says to replace a part, further testing to find the REAL problem is required. You may have wasted your hard earned cash on a new cat.

 

Yeah correct sensor and everything matched up color wise. Its so weird. I can't figure it out. Getting the intake duct replaced tomorrow, hopefully that will fix everything, but doubt it. Fingers crossed.

I replaced with OEM style plug sensors. Both O2 sensors were replaced.

 

P0054, says the calculated resistance did not fall in the expected range. This code points to the O2 sensor #2. Take the connector off the O2 sensor after the catalytic converter, make sure you see 12+ V on the PNK/BLK wire with key on, engine off, and then measure the resistance across the leads that mate with the PNK/BLK wire and GRY/WHT wire. They usually fail open. It's possible that you got a bad part. Also there is a fuse for the heater circuit in the under hood fuse box.