I have a 2005 Toyota Corolla. Check engine light came on last year. I replaced catalytic converter last year, both O2 sensors last week and have added a catalytic cleaner recently and followed the directions to a tee. My check engine light is still on throwing that code. Any other suggestions what it might be?
It’s a bad cat converter. find out what killed it. Fix that. then replace the cat with a new one
Okay… It’s got 263k miles on it but I’ve taken great care of it for years. Just not sure how much I’m willing to pay at this point to properly diagnose. Hopefully they wouldn’t charge me a fortune just to diagnose but they probably will. It runs mostly fine just notice gas mileage isn’t as great anymore.
Take a rag and hold it over your tailpipe for 5 or 10 seconds at a time. See if you can hear the exhaust hissing out of anywhere upstream of the catalytic converter. Flexpipe, midpipe, exhaust manifold. Even better if you have someone else to hold the rag while you listen.
Another method would be to make some soapy water, the consistency of the stuff you blow bubbles with the wand. Liquid dish detergent and water in a spray bottle. You can spray the exhaust before it fully heats and see if the soap/ water mix bubbles anywhere. This works if you can get underneath the car to visually inspect while doing it.