How common is cat failure on a '00 XJ8 VDP? I just got it about 4k miles ago. It has 104k miles. CEL came on yesterday in traffic. Cat failure code PO420. I cleared the code, but I know a cat replacement is coming soon... Anyone else have to deal with this?

 

I did a good BG 3 part fuel system service. Ran through injectors, Throttle-body and 44k in tank and it cleaned mine. i had one that was lazy. That was 20k miles ago and all is well.

There are some methods that will clean them. I have seen where they pour a gallon of turpentine in fuel tank and if does not work they soak it in a pale of soapy water.

 

Nice to know. I'll give the BG a try.

Thx.

 

I recommend 2 cans of seafoam in the gas tank and half gallon of Lucas fuel treatment as well then a full tank over, then floor it. Get it up to 105 then floor it to 130. Repeat four or five times. You will never see that code again. \0/

 

Otherwise known as an "Italian tune-up"

 

brutal.... who sells the O2 extender?
tried another oxy sensor and that P2a01 came back again so the big daddy mini cat might not be a solution