Hey Scotty, I just wanted to tell you to stop telling people they can ignore a P0420 code. You do have to fix them. I ignored my P0420 code for 4 years because I thought my 2006 Sienna was just picky about the aftermarket cats I had put on it in 2021. Wrong. It started rattling in Dec 2023 but we didn't know where the rattle was coming from. In June 2024, we tried to take it on a road trip from Virginia to Memphis TN, we stopped at the rest stop just before Bristol, got back on the interstate, only made it one exit down and the car just stopped running. Engine wasn't running hot or anything. Felt like the transmission was just slipping, and it wouldn't go over 10mph. We limped it onto the exit to Blountville, and were stranded there for a night while we figured out what to do. Had it towed to a shop in Blountville the next day (Monday), got a rental car, and continued on our vacation, guy called us on Friday after looking at it, and turned out the catalytic converter overheated. Shout out to Brian's Auto Tech and Transmissions in Blountville for fixing it and being honest and kind btw.
Lesson learned, don't ignore a cat converter code. Especially on a hundred degree day in the middle of nowhere Tennessee on a road trip with 3 kids and your 80 year old grandmother.
stop telling people they can ignore a P0420 codeWhen did Scotty say to "you can ignore a PO420 code"? A flashing CEL means attention required immediately , a non-flashing CEL means attention required soon. A PO420 code typically causes a non-flashing CEL. Regardless, a PO420 is a common code but it does not mean "you definitely have a bad catalytic converter". Many things can cause this code: https://www.obd-codes.com/p0420 and none of the causes for it should be ignored.
In the case that the catalytic converter is clogged, then of course it needs to be addressed. You'll know by the loss of power. If the code is just being caused by a cat that's worn out (not collapsed), you can keep driving. There are many causes. Exhaust leaks, bad sensors, etc. etc. Scotty never told people to ignore check engine lights. He always scans them, diagnoses (using a back-pressure test or whatever), assesses the situation, and then decides how to proceed.
The rattle should have been an immediate red flag for you.
