I am getting a check engine light which comes up as trouble code P0442, which is a small evaporative emissions leak. I have replaced the gas filler cap but that has not solved the problem. My car is a 2003 XK8.

Any help would be appreciated. I have searched this forum but have not come up with anything.

 

many posts on that very subject, its most likely a canister close valve (purge valve) partially stuck open. Mine had rust in it from the vent tube corroding, and both were replaced. No more problems. Others have just changed the valve.

 

I had a much simpler cause to this problem on my car. The hose between the "evaporative emission canister vent solenoid" (#5 on JTIS diagram) and the canister (location: pass side rear by petrol tank) was cracked in about 3 places. The correct hose was $8 from the dealer but I'm sure you could get the proper size fuel rated hose from a local auto parts store for considerably cheaper. I tried the gas cap first too. Lesson learned, look under the car first! You don't even need the car raised to see this area. It is worth a quick check for the several minutes it will take.

 

Thanks guys. Looking at old TSBs it seems that there were a lot more problems with the early XKs. However, looking at the JTIS, it seems that Jag completely re-engineered the evap emissions system with, or before the '03 model. You both have 03 and 04 models just like mine.

Is there a way of inspecting/ testing the purge valve visually/mechanically, without a bunch of electronics? I do have a multimeter but thats about it!!!

Thanks, took it out in 49C sunshine with the heat full on in the face vents today. Not many days like that in WA for the next few months!!!