Hi All, read through all the existing threads on this (seems to be a common issue) and tried all the drive cycles listed as best I can but still no sign of the Catalyst Monitor completing - which means I can't get a smog test and therefore can't transfer into my name thanks to the California rules... I could go back to the seller (who should have got it smogged before selling) but there's not much more he can do and I do want to keep the car ideally...

So my question is this - does anyone have the definitive drive cycle for this model from Jaguar? I'd feel better repeating something multiple times if I knew it was definitely the right procedure etc... Any help would be much appreciated!

 

It takes what often seems forever for the system check to complete, 300 miles is not uncommon, but here is a reply to another XJ owner regarding the drive cycle details..........

https://www.smogtips.com/smog-questi...itor-Readiness

 

Thank you - unfortunately I have tried those suggestions already, and driven over 600 miles so far with no luck.

Is it worth me getting a garage to manually check the emissions in case there is an actual problem with the cat? Or would that give a different error code? Starting to think that's the most likely issue.

 

When something is wrong such that one or more monitors won't set, many codes also cannot be flagged.

If you're lucky a pending code may flag but otherwise to a fair extent it's like diagnosis in the days before codes.

Sometimes you can eyeball a sensor reading and figure it's wacky. Or read tailpipe gases and see something wrong. Or ... well, you get the idea - it can be painful.

Sometimes codes were deleted and the owner can use those to figure a fix. Sometimes fairly recent work was done and that can be a clue.

 

Just about ready to give up, as is my garage who has been helping - they say everything looks and is testing fine but I've done over 1k miles now and can't face doing any more endless drives to nowhere!

So, one last desperate request for anyone with any experience or success on how to get a reluctant cat monitor to clear, I'd love to hear...

 

Update for anyone that is having the same issue - the garage managed to narrow it down to faulty upstream oxygen sensors even though they weren't giving any errors and were passing the tests. Both were changed and the cat monitor cleared easily and the car passed the smog test his morning :-) They also put in new plugs and a replacement coil, which may have contributed to the problem initially, but it was replacing the sensors that got the cat monitor to pass...