Hi Scotty,
I have a 2009 Corolla S w/ an automatic transmission and 137k miles. About 4 months ago the check engine light turned on and I found out it needed a new down stream O2 sensor. I bought a new OEM one and had my mechanic put it on because I couldn’t get the old one off. The code went away but now it’s back. Any idea why the new one went bad too? I bought the car when it had about 105k and suspect that the previous owner didn’t do proper maintenance and I’m worried it may be the catalytic converter.
Ps- thank you for everything you do. I watch your videos every day.
~Josh
If you are worried about the converter, crawl under the car when it is cold and smack the converter. If you hear what sounds like marbles in a can, your internal baffling has broken and you need a new converter.
