Tony Alonso

I have 38,700 miles on my '07 GT and had the check engine light come on 2 days ago. The Ford service department diagnosed the issue from the code P0430 ("catalyst efficiency below threshold - bank 2") as a failed rear oxygen sensor. I've not had one go out at this mileage in other vehicles this early. Also, this was not covered under 2007 emissions warranty.

I do have the sensor in my possession, so I plan to get someone to check the voltage.

Has anyone else seen an early sensor failure? Thanks for any input or comments.

frdtch05gt

I have seen oxygen sensors fail early, like at about 40,000 miles or so. It does happen from time to time, just luck of the draw. I don't think there's very much you can do about it, other than replacing the failed part, even if you need to pay for it. If it had been the converter that failed early, they would warranty that.

J2L06GT

Read a report about O2 sensors that said if you really wanted
any car to run most efficiently you should replace all of them
every 30k mi, but car manufacturers don't put it in maintenance
manuals so they don't have to cover under warranty.

Tony Alonso

Thanks for the replies. I am thinking this one that failed might have been nominal. I noticed that after this was replaced, I stopped getting exhaust popping (which I was thinking might have been some backfire) if I started driving the car within 10 seconds after starting. I thought I had read somewhere one here that some were thinking this was pressure being equalized in the H-pipe causing the noise after the car set and was cool. I think it might have been an O2 sensor that was on the edge.