Anybody having a problem with this? I have a customer that says this is a major problem and it is new to me. He has a 00 Tundra with 45k miles, flowmaster cat backs, K&N filter, and everything else is stock. Someone give me a shout.

Todd

 

Its fairly common and generally happens between 35-60k miles. My 1st sensor went out at 55k and I just had the other go out at 63K

 

3.4L or 4.7L?

You said cat back(s) which leads me to believe you are talking about the 4.7...

Not sure though.