P0420 code. Iv'e replaced US and DS O2's, IMT o-rings and PCV Hose and now am getting set to change the rear cat. I bought this Jag faily cheap because of the the bad cat but only had about 67,000 miles so it failed fairly premature. The car has a bit of hesitation around 1400-2000 RPM and will ocasionally go into LHM with the lovely "Cruise Not Available" message.

1. Am I going to be ok with a non California legal cat (I dont live in CA) or will the OBDII be picky about it and throw a CEL? Here is one I'm considering: http://www.carparts.com/details/Jagu...avicodav181081

2. Is there anything else I should be looking at that may have cause the cat to fail?

3. Should I just replace both cats at the same time or save the cash for when the front fails later?

Changing the front cat doesnt look like the intense job that the rear will be. Anyone change one of the front converters before? Does it require subframe removal like the rear?

Thanks!

 

02 X-Type 3.0 for reference...

 

So I'm guessing 02 wasn't the 10 year 120k warranty right? Might want to verify first if you haven't. Mine seems to have just been an random code as it hasn't come back after a good cleaning and some sprited driving. Even if it wasn't necessary, it was fun.

 

stshots, removing the front cat does not require removal of the subframe as you should be able to slide it out the top of the engine bay. Unfortunately, the rear one is not so easy and does require more removal of car parts. As for removing the front cat at the same time, honestly, I would tell you to spend the $100 to have a professional connect up one of their OBD scanners to the car (unless you have access to one that shows real time data) and see what the O2 sensor is indicating. That will tell you if the cat is in need of changing or not. If I remember the numbers correctly, you are looking for under 0.5 VDC on the downstream O2 sensor. If you are seeing the front get up near that, then probably would be a good idea to change it out. But, if it is down around 0.1 or 0.2 VDC, then it is still good and save yourself some money. You can use the bad cat as a reference since you will be able to see both numbers at the same time.

 

Benebob, yeah, its the 8-80,000 warranty on the emissions. Just missed it :-(

Thermo, thats a great idea. I have a PC-based OBDII scanner on the way. should be here in another 4 days or so. I'll be able to run it in real time and see. I also want to watch for any other vacuum leaks to see if I missed something.

Anybody have any luck trying the aftermarket cats?