Check Engine Light

[argonaut1992]

My check engine light came on yesterday. After getting the code from the diagnostic computer the dealer told me to make sure the gas cap was on tight. They said it makes the onboard computer think there is a major vacuum problem it it is not on tightly. So far it has worked. Just in case any of you run it to this. If you hear of some other cause of this please let me know.

[keiffers]

Could also be your O2 sensor. Had that problem on my Tundra, with less than 20k on it at the time.

[bigmd10]

Ya this happens with all my vehicles, if you dont put the gas cap on right the engine light comes on

[DougC]

My wifes Quest had the light on continuously for the first 1,800 miles and they found the harness loose after replacing the TPS/adjustable pedal assy (tearing the dash out to replace), breaking all the clips and greasing up the leather etc. (Sorry about that) Don't know how many miles are on it, but..........

[hwwaaahhhhh]

My light came on, i took it in and they said it was the O2 sensor. They replaced it without any problems. If you start seeing your gas mileage drop, it's probably that.

[cgfitzp]

My light camr on on Monday.

I had an appointment today to fix the 4WD lights.

They fixed the light by "flashing the computer" service manager said that meant updating the firmware. Any way the light went off.

[keiffers]

I'm thinking maybe I have a bad O2 sensor, and that just reminded me that I forgot to ask them to look at that while they have it to replace the radio. My mileage since I purchased end of June averages out to 11.5 mpg, so makes me wonder if there is some problem, whether it be the O2 sensor something else. most postings I see about MPG is up around 14-15 and even some 17 and 18. Granted I drive in the city 95% of the time, so that may affect it obviously, but still. I averaged 14-15 on my Tundra. I never expect to drop this much