Contour Enthusiasts Group Archives Forums General Troubleshooting Engine Light - Fuel Cap possible

I took my car to AutoZOne and had the check engine light read on my 98 CSVT. Came up with the P0455 or 442 code (I can't remember which), but the guy told me that it was bad fuel code or gas cap code. It has happened 4 times since then and I took it back to Autozone again and it was the same code.
So I went out and put on a new gas cap. Still does it from time to time. Light comes on when I get about 1/2 a tank of gas. Also found out previous owners had also had a new gas cap installed by ford just before I bought it.
I run octane boost or 93 Mobil in my car, but still have to use the crappy 10% ethanol here in the midwest, no getting around that. Any suggestions on a remedy? Seems like a long running problem in the history of my car although it just started doing it to me after 10,000 miles of carefree driving. Why now?

thanks

P0455 Leak or Blockage Detected in Evaporative Emission Control System.

PCM monitors the EVAP system for no purge flow, and the presence of a large fuel vapor or several smaller ones.
The system fails when there is no purge flow ( attritubed to fuel vapor blockages or restictions), a large fuel vapor leak or several smaller ones by the EVAP running loss moniter test running, but not at idle.

Causes
-aftermarket EVAP hardware, such as fuel cap different from OEM
-disconnected or cracked EVAP canister tube, EVAP canister purge outlet, or return tube
-EVAP canister purge valve stuck closed
-damaged EVAP canister
- damaged/missing fuel cap, also cap not correctly installed
-loose fuel vapor hose/tube to EVAP components
-block restrictions in fuel vapor tube hoses
-fuel vapor control valve tube assembly or fuel vapor vent valve assmebly blocked
-canister vent soleniod stukc open
-mechanically inoperative fuel tank pressure sensor

hope that helps

Lots of help, thanks.
Where is the EVAP cannister located on the CSVT? I figure looking at it this weekend.
Thanks again.

The fuel or the fuel additives you use have absolutly nothing to do with either of those codes (or any other codes).

Try to be specific as to which code, exactly you have. The diagnostics are a bit different.


Steve