Why would CEL on-off intermittently
 

My 02 2.7 has the CEL coming on and off with different fueling( so it seems ) the wife gets gas when ever its needed and not always at the same gas station,..But in the same town Tucson,az ...So maybe the additives or maybe gas cap..?? the CEL is on more than off even with 1 02 cable changed out,I think its on 60% of the time ??? Thanks Frank

I am pretty sure you have a bad gas cap!

I was kinda thinking the same thing,..I thought maybe the different fuels,.also,..but Ill get a new cap today..Thanks

For reference, here are my old and new gas caps. If yours looks cracked like mine was, change it.

Also, in the future, buy yourself a Durametric or Foxwell tool to read the CEL code. They quickly pay for themselves!

http://986forum.com/forums/uploads02...1561988944.jpg

I have not looked at the old one yet but I did pick up a new one from Porsche for 20.00,..sure hope that's it..I bought all new O2 sensors but I cant get the connectors off . Thanks Frank

Any muffler shop can swap your sensors. Doesn't need to be a Porsche specialist at their rates. Just takes a bit of lift time to let the exhaust cool down before they go at it. Maybe 15 minutes for the first one. They have the tools. Did mine that way.

Just make sure they are the right Bosch made sensors with pigtails crimped to the sensors.

What is the CEL code?

I dont have the Durametric tool to get the code,..I did replace the gas cap on 7-1 so far no more CEL.

Oh,..Thats a good Idea Mike F. Thanks,..I will look into that aswell. !