Got the car from the dealership yesterday after the car threw a P2A02 code. They said I have a clogged cat and a bad Air Fuel Sensor? Cat is covered under warranty, sensor is not.

My question is...are there both upstream o2 and a air fuel sensor? I've looked on rockauto.com and they have a upstream o2 sensor listed but no air fuel sensor listed.

It looks like I'll be replacing the sensor but I have zero clue since I have yet to begin taking apart anything because the dealership is going to take a half day to replace the cat on Monday or Tuesday...yeah, half a day for a cat swap...

 

What year car do you have? Early Z's have 1 o2 sensor upstream, and 2 in the cats, but late model Z's have 2 upstream o2 sensors.

 

2008. I just don't understand why they are calling it a Air Fuel Ratio Sensor. To me, that is just the more advanced style of O2.

 

had my 08z cat replaced yesterday at the dealer too due to p0430. under warranty.

on my paperwork it shows they "stripped air/fuel sensor upon removal" so they replaced that too.. i guess this is what theyre calling an o2 sensor?

if it is only an o2 sensor, idk why it wouldnt be considered a part of the emissions system and get replaced with the cat?

 

Looks like I have an appointment Wednesday to get the cat replaced, and yeah...they said if it was the downstream o2 it would be covered under warranty, but since it's the upstream "air fuel sensor" it's not covered.

 

Simply for future knowledge for those that get the same engine code I did.

Dealership kept stressing it was the cat and the O2 sensor. This was false, once the cat was replaced the engine light went off and the car's gas mileage returned to even better then when I purchased it in 2011. Turns out the cat was clogged enough to cause the gas to pass so slow though it, it would trip the upstream O2 sensor.