Dear Car Talk Community,
The check engine light came on and I went to the mechanic. He said that it was because of a leak of fumes from the tank (either because the gas cap was not on correctly or one of the sensors was blown). So he cleared it and said I could go for the smog test after driving it for a few days.
I drove my car for a few days (after 60 miles), I went to smog check. (At this point the light was not on). However the smog check faild because the “engine light” had not cleared. The smog testing guy also told me that the gas cap failed the test. (however it could also be one of the sensors).
So I drove another 120 miles or so and still the check engine light has not come on. Do you think I can go for another smog test now since the light has not come on? (this would be a free test since this smog testing guy has a free retest within 30 days if test failed).
Please advise me!
Thanks a lot in advance.
I forgot to mention: I bought a new gas cap and then drove 120 miles.
It will probably be OK now. The monitor for that system should be able to operate after a couple days of normal operation. It may require a couple shut down periods when the car gets to cool off enough between starts.
Since it hasn’t cleared, you may have a problem somewhere else in the system.
“The smog testing guy also told me that the gas cap failed the test. (however it could also be one of the sensors).” I wonder HOW the gas cap was tested. If the method used was to take the gas cap off and vacuum or pressure test it, I’m not convinced that that is a valid test of the cap.
“However the smog check faild because the “engine light” had not cleared.” I don’t quite understand this statement. I will assume that the trouble code didn’t set. The “system ready” may not have completed. On the scan tool screen, the monitor symbol would be flashing. Your mechanic should be knowledge of the monitors.
He may have to school himself on this.