Simple question, what are the specs for the fuel cap seal (gasket). I want to replace the rubber seal on the fuel cap without having to buy a new gas cap ($56 USD) for a 2000 XK8 convertible. Trying to run down the P0171 P0174 codes.
I’ll be cleaning the MAF sensor, and try to see if there’s a leak too, but the seal is precautionary.
there’s many seals out there of various sizes, and I want to make sure I get the proper size.

 

Faulty cap seal will flag P04xx EVAP codes. (not lean codes)

 

Check both of your VVT solenoid O-ring seals. They bake in the engine bay, get hard and brittle, and start to weep oil (and air). That may be the cause of your P0171 / P0174 OBDII codes....