The local gas station had run out of regular gas, so the premium was offered at a good price. But soon after the fill-up my check engine light came on. About 3 tanks of regular have been through my '03 vibe since. Any thoughts are appreciated. Thanks!
Could be a coincidence. Might have been bad gas, but I suspect not since you didn’t report any performance issues.
Go to AutoZone or Advance Auto Parts and they can read the codes set by the check engine light. Post them here (exact code, not anyone’s interpretation) and someone may be able to help you.
You can be virtually certain that the light has nothing to do with the fuel you used or are now using. But your car is definitely complaining about something and you need to find out what it is. Likely it is something minor – still, you want to know.
Follow jayhawk’s advice about getting a free scan at either of those places. You will be told a trouble code and you can post back here.
It is not the gas. 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.
It’s possible that if the station had run out of regular, they were close to running out of premium too. You might have picked up a tankful with a lot of water or dirt in it. If dirt, there might still be something clogged up somewhere (filter, injector, …) after three tanks of good gas. Any impact on performance?
My experience is that both dirt and water stay at the bottom of the tank, where the pickup is. It seems like a low fuel level would have little affect on this. (If you’re pouring out of a can then yes, but pumping out of a storage tank with a fixed pickup then no.)
Gas can set a check engine light, even if the car seems to be running fine.
This past spring in the Boston area, there were a number of gas stations that got their gas from the same supplier. Many customers at those stations all of a sudden had their check engine lights come on. IIRC the codes were about the O2 sensors and catalytic converters. I don’t remember anyone reporting driveability problems.
You can imagine this hit the news quickly and within a couple of days they tracked it to the supplier. There was some additive that was added or was overly concentrated that was causing the problem.
It doesn’t sound like the OP has this problem.
the man at autozone said the code was P0441. something about a purge valve? he reset the light and said if it comes back, come back! the car has been runnning fine. thanks to all for the discussion!
P0441 - Evaporotive Emission Control System Incorrect Purge Flow.
The ECM is detecting a problem with the charcoal canister purge system that may be a blocked up valve or a pinched line. Either way, the system is not purging the fumes collected in the charcoal canister like it should. It may be a bad valve, or just a clog in the system. If the light does come on again, take it to your mechanic, and let him fix it right.