Are the sensors the same? I've done a bit of research but they point in every direction.

From what I gathered, AP1 (00-03) are definitely different from AP2v2 (06-09). How about AP2v1 (04-05)? The part numbers show that all 3 generations are different.

I have an 04 and was sold an AP1 secondary o2 sensor and it now throws P0141 (o2 sensor circuit malfunction) and I'm guessing the incorrect sensor is the culprit.

 

Seems like you answered your own question. I don’t think Honda would change the part numbers without changing the actual part.

 

From what I recall, some parts did have different part numbers but are interchangeable with different model years. I'm just looking to see if anyone can confirm my theory and research.

 

Your sensor is bad, according to the code you listed. Putting an 04-05 sensor in an AP1 will not cause that code. Did you get the sensor used?

 

Well, I've been running for 50k miles with no issues, with stock ap2 o2 sensor, and a stock ap1 cat.

The car is an '06 ap2, o2 is stock. Car came with junk ebay cat that fell apart inside. Replaced with low mileage stock cat, but from an earlier ap1 car.

 

The catalytic converter part number changed in 2006 with the DBW cars. Not sure what changed but the part numbers are very different in the last six digits. I'm thinking the sensors are the key as Berk high flow cats have worked with out codes in my '06 and buddy's '02 with the original OEM sensors.

-- Chuck

 

I put an AP1 sensor in my 04-05, but yes I got the sensor used. The seller is reputable and sensor came off his personal AP1 with 33k miles. He's sending me another sensor from an 05 so hope that will solve the issue.

 

What changed in oem cat is o2 sensor location. But the o2 cables are long enough that any oem cat works in any car. The sensor position change isn't going to cause a code.