I'm having a little problem with my 2001 Jaguar XK8 convertible. I have just replaced the upper oxygen sensor on bank one and the car is now running a little rough but smooths out after it warms up. After driving about 10 or 15 miles and now get a 420 catalytic control error on bank 1 the same one I replace the oxygen sensor on. I have been a backyard mechanic for many many years but I don't have any of the sophisticated Electronics Equipment other than a little cheap code reader or any specially tools. I doubt very seriously that the catalytic converter is bad and I've read a bunch of descriptions describing the 420 errors and what the possible solutions for them. My question is since the new sensor was installed should I have also replaced the lower oxygen sensor on bank one? I really just don't wanna start replacing parts 'cause they're not exactly cheap and some of them are pretty hard physically to replace :-). I don't think Jaguars are noted for their plentiful room to work like a 1950s Chevy. I mean to replace the oxygen sensor your supposed to take off the entire exhaust system. Really!!!

 

Always look in the Sticky's at the top of each forum...first off your kinda in the wrong forum, this is the X308 section, you want X100. Here's yours....https://www.jaguarforums.com/forum/xk8-xkr-x100-17/
When you do any vehicle code check, put the vehicle name and P code to get more specific returns on searches....example...Jaguar P0420...any pulled code returning just 3 digits you simply put a zero in between the P and the first number as shown.

Review this write up I did, your engine bay is a bit tighter, but the process is similar, but maybe it will give you some confidence.... https://www.jaguarforums.com/forum/x...cement-195018/

 

I appreciate your helpful information. I have listed it in the right forum now and I changed the title as you suggested. Thanks again for your help Doug
I have not figured out how I can delete this post in this part of the forum.

 

At the bottom right of all the forums is a list of Mods...just prompt one, PM them...and ask them to delete it for you. Good luck with that 420.