$1,000 later. Just before this it was a bad ECM. Wrangler Fix ECM fixed all kinds of issues. I love my jeep, I love my jeep, I love my jeep.... lol
Last edited:
P0421 code fixed
- Thread starter KtsTJ
- Start date
Hopefully you don't have to worry about this again for a while.
I suspect there's a lot of old TJs with failing cats and that is causing a lot of headaches for people who don't even realize it.
I suspect there's a lot of old TJs with failing cats and that is causing a lot of headaches for people who don't even realize it.
OP
LONGJP2
TJ Expert
OP
Flowmaster. I have a Flowmaster cat back exhaust. It was $150 more than walker brand on rock auto at the time. figured might as well go with the flow master. Found a good deal on Ebay.
Bash me all you want , but every 05-06 I have dealt with that has any miles needs 02 sensors, cats, and a code reader in the console.
I just did the Y pipe on mine and sensors, well worth the money after the PO straight piped it from the engine. Jeep has much more power and is way more joyful to drive.