I have a 2005 X-type wagon that I’ve had for many years. It’s having a bit of trouble lately.

 

It’s throwing a P0420 code. I recently changed the spark plugs under regular maintenance and then this. Changed the upstream O2 sensor and drove it 50 miles. Drove 1/3 way back, P0420 again while idling at stop light. Came home, cleared code, drove it to school and back and no code. It’s intermittent. Any suggestions? The car won’t pass SMOG inspection until I get this fixed.

 

Welcome to the forums Heather,

You've obviously researched P0420 as the lookup shows it as a bank 1 HO2 sensor (either upstream or downstream) fault or failed cat. When you clear it, it will come back after 2 'trips' unless the cause is resolved. Co-incidence happening after the plug change so any chance of a disturbed harness connector?

Follow this link https://www.jaguarforums.com/forum/x-type-x400-14/ to the X-Type forum for help, advice and information. The 'HOW TO' thread at the top is a good place to start for information on regular issues. You can also use the US Western Region forum by following this link https://www.jaguarforums.com/forum/us-western-38/ to find other members in your region.

Please read the guidance for new members ( https://www.jaguarforums.com/forum/n...ned-up-241802/ ) which answers many of the most frequent questions about getting started.

Enjoy the forums.

Graham

 

Welcome to the Forums.

 

Welcome aboard Heather.

 

Welcome to the forums.

 

Welcome to the forum Heather,

Good to have you with us.
Enjoy the forum.

If you haven't done so already you should add your car details to your signature to help others to help you.

 

Hello, Heather,
Doncha just Love Intermittents? I hope you can get that resolved in plenty of time for your SMOG test.
Welcome to the forums from ElinorB.
(';')

 

welcome to the forum - enjoy