Service engine light

I put 12-15 gallons of aviation fuel in my 2000 GMC safari van, and drove 40-50 miles and the service engine light came on. When i stop the car, theres a faint smell of gas, but no leaks. does anybody have any suggestions on how i can fix it?

That CEL (check engine light) is just a kid in class waving her hand trying to get you attention because she has the answer. You need to have the codes read. Some places will read them for FREE. Try Autozone or Advanced Auto Parts. Get the exact code (like P0123) not just their translation into English and post it back here.

The guy at autozone checked for the code and he got P0440. He said it was evaporation emission control.

Thank you for posting the code. I just gotta asking, but why avgas? Premium grade gasoline not expensive enough?

P0440 - Evaporative Emission Control System Malfunction.

Check to make sure the gas cap is on tight (2 or 3 clicks) and check the gasket surface of the gas cap for signs of wear or damage. This is a generic code for a detected problem with the evap system.

The evap system is designed to keep fuel fumes from escaping the gas tank and fueling system by capturing the vapors, holding them in a charcoal canister, and then purging the vapors at key times through the engine to be burned. The ECM controls the purge valve to that will pull these fumes from the canister and into the intake system.

If the gas tank cannot hold a vacuum, this code is generally set. The most common cause is a loose gas cap or damaged gas cap gasket. If the cap checks out OK, The gas tank may have to be dropped to look for more vacuum leaks.

ADDITION: Also check the vacuum lines under the hood. Teh evap system gets vacuum from the engine, and this code can be set if there are vacuum leaks in some of the evap hoses.

a friend of mine sold his plane and the new owner wanted the tanks emptied so he could put fresh fuel in. Me being cheap i couldn’t see wasting 15 gallons of perfectly good avgas. PS: thanks for the help, i’ll let you know how I make out.

Doesn’t aviation fuel contain lead? If so, you can say bye-bye to the catalytic converter(s) and the O2 sensors.


avegas is high octane unleaded, do u think the avgas is the cause or just a coinsidence, if it the cause would the fix be an egr valve ,evap solenoid or O2 sensor before it would be vac. line or gas cap? thanks for any help u or anyone else gan give.

I asked because here’s what it says about aviation fuel.


could problems start with 12 - 15 gall. or would it take cointinued use ?