Mid-grade gas cause CEL??

[sgolden183]

i put a full tank of mid-grade gas a week or so ago, now im at a quarter of a tank and my CEL is on, i refilled with mid-gradde, and its still on...does mid-grade cause a CEL?

 

[DiS]

meh there are too many variables to blame the mid-grade gas (83 octane I presume). Our cars are actually intended to run on regular gas from the get-go, but low grade gas overtime can cause pinging and such. Not to rule everything out, but this is the worst case scenrio: people at the gas station mixing gasoline with other crap like water. Yes, I've seen it done in person.... unfortunately. This case is highly unlikely, but cannot be ruled out.

Did you check what CEL code you're getting? It is possible that the reason why you're getting a code because of the eVap system faulting up. How many miles on the car? How many miles on the spark plugs? Are you the original owner? If so in what intervals was the maintenance done?

 

[derfernerf]

Mine does this too between half tank and 3/4 tank. And then once I hit half tank my gas gauge reads wherever it wants (Completely empty sometimes)

if you're worried about the CEL being something else, after you fill it up, reset the ECU (disconnect the + battery terminal for a few minutes) and see if it goes off, which it should

 

[DiS]

Resetting ECU will briefly get rid of the light. It's like a bandaid. Meanwhile the problem will still be there.

 

[derfernerf]

Resetting ECU will briefly get rid of the light. It's like a bandaid. Meanwhile the problem will still be there.

Yes, but it makes sure that this is his only problem.

 

[DiS]

Yes, but it makes sure that this is his only problem.

Still, getting a CEL reading is a smart idea before resetting ECU.

 

[sgolden183]

i am the original owner, 40,000 miles on the entire car and i haven't changed the spark plugs, but i will in the near future, and i havent checked the CEL code, but i did reset the ECU and it went off, ive driven about 250 miles and it hasn't come back on, im using 89 octane.