I purchased a 2005 XK8 several weeks ago at what I thought was a decent price. Almost immediately started getting Check Engine warning - code P0420 (catalytic converter problem). Took it to an independent shop for some other issues and to address warning light. Had brakes replaced, new therm housing, antenna mast, battery, and a few other minor items. Also replaced some kind of leaking housing with the fuel system (sorry I'm not too mechanically inclined) and reset the warning code and told me if it came back I would probably need a new catalytic conv. Meanwhile had the car detailed and it looks great. About 100 miles later the CEL came back on. So I was mentally prepared to replace the cat. conv.... until I researched on this forum and found out that there was some kind of Federally mandated warranty on cat. conv. for 8 years or 80,000 miles. So yesterday I took it into the local Jag dealer and for sure it was the converter and will be covered at NO CHARGE - even at 78,570 miles - saving me @$4000!!! (probably less for an after market replacement). So... THANK YOU forum members for being such a great source of information. It also makes me wonder if the PO knew about the problem but not about the warranty???

 

Yeah, I'd say a little time on the forum can save some big money. You've got to be feeling pretty good about that. Now take that money you would have dropped on the cats and take your wife to Paris instead.

 

Great info Resneed!! I have an '05 XKR myself. Only 56K miles, but this is some useful information.
Thanks Bro!

 

Send me that $4k you saved!

 

Sure... Check's in the mail .

 

UPDATE: About 800 miles after having the bank 1 catalytic converter replaced the CEL came back on. Code 0430 - bank 2 cat. conv. Back to the Jag dealer with 79,368 miles. They are currently replacing the second converter at no charge with 632 miles left on the warranty. I must be living right or something.

 

Of course you are, you own a Jag!

 

Wow... Good for you. I have atleast 2 years before I hit 80K miles, so I may never get to take advantage of the warranty.

 

Only logical reason for both cats reaching that point is being driving too long with multiple misfires and the PO not fixing the problem soon enough. I've had one misfire during my ownership; it being due to a cracked coil-on-plug (COP) and I was afraid to drive it 5 miles to the auto parts store. I did rather cautiously, but brought my tools with me and changed it in the parking lot to limit driving it in that condition. I even bought a spare COP and now keep it in the boot, because when these fail, it can be anywhere, and sometimes instantly. I don't want to risk damaging my cats...I can't afford one!

 

Thanks for your comment. I haven't noticed any misfires since I've had it and the mechanic checked the plugs when I took it in right after I bought it and said they looked fine. It does seem to be burning a little oil but not too seriously. Maybe there was an issue the PO fixed before selling. I'm still suspicious that he probably knew about the cats... but didn't know about the warranty.

 

Either way, you benefited from someone else's error. Good for you!

The misfire is easy to detect, and you'll get a CEL with a restricted performance message if it happens in two successive drive cycles. As long as you're prepared what to look for and know how to deal with it, you'll be just fine.

Burning oil isn't normal on these cars, especially as new as yours is. It wouldn't hurt to run a couple cans of BG-44k through the fuel system. Did you change the air filter with your recent service too? you could also remove and clean out (or replace) the PCV line from the right hand side valve cover that returns to the lower elbow of the plenum under the throttle body. If you look past the TB plate, you'll see lots of carbon deposits, but excessive manifold pressure I suppose could bring oil back up that far...like the older 4.0L engines were prone to when their part load breather plugged up.

 

Along with the required tools and scanner to locate which coil no doubt?