Some background...
07 X-type 3.0 AWD
I washed my engine. After that my car was running rough and misfiring. Check engine light came on. The check engine light would flash when I drove it, but I did not drive it far. I pulled the coils and realized that there was water in the wells. I dried them, and replaced all of the spark plugs and coils. The car ran great.

Now...
After driving about 5 miles (since the new plugs and coils) my check engine light came on. I have one code, P0420. Catalyst System efficiency bank 1. The car runs fine, and the exhaust smells fine. Does it sound like I need new cats? I don't feel like I drove it enough to do damage. Is there anything else I can check first? Is it possible the code could clear up after going for a good drive?

Thanks!

 

It might be a bad o2 sensor. Check the site. I believe that is the up stream o2 sensor.


Good Luck,
The Dr!

 

pdfisherman,


I see you are located in Boston; I am about 60 miles north of Boston. As you know, we have had some great weather this week, with temps in the 50's, and I was also out washing the cat on Christmas day (but not the engine!). Too bad we did not have record low blizzard-like weather, then you would probably not be having this problem.


It seems unlikely based on the scenario you gave that the catalytic converter is damaged, especially since you were quick to attend to the problem. The code you are getting indicates the oxygen sensors have determined that the catalytic converter is operating below the threshold efficiency. My trusty mechanic always tells me most p420 codes are due to bad oxygen sensors and not the catalytic converter itself. His advice: if the car appears to be running fine, erase the code, and drive the car with your fingers crossed. If it comes back, you can try a bottle of catclean and repeat the process. If the converter got contaminated due to running too rich, it may help. However, if the catalytic converter was damaged due to getting too hot, the catclean will not do you any good; overheating causes agglomeration or sintering of the precious metal particles, and the only cure for that is to replace the converter.


Best of luck and let us know what happens!

 

Thanks for the advice.

You're right, sawduster, if we hadn't had this nice weather I would not be in this predicament! (Or I should have just been smart enough not to wash the engine!)


I cleared the code, and it came back within minutes. I cleared it again when I parked it this afternoon so we'll see what happens when I drive next time. I think I will look into the O2 sensors before getting a new cat. I kind of just assumed it was the cat. If I don't have luck with the O2 sensors I'll give the catclean a shot. We'll see what happens. Thanks

 

I assume you "trusty mechanic" doesn't specialize in Jaguars. If you are looking for the least expensive to turn off the light & get a sticker try one of these. I can tell you first hand they will work.Search Results : Innovative Performance, Home of Voodoo Manual Turbo Boost Controllers

 

Around where I live there aren't many Jaguars, and no independent Jaguar mechanics that I know of. Hence, if I can't fix something myself its either off to the dealer ($$$$) or take my chances with the "we fix all brands" mechanics. And if I try to tell them "the experts on the Jaguar forum said to do this" they really get insulted. But, it's really just a Ford underneath, right? (Or so says my "trusty mechanic")