Check engine light on after adding #91 gas to a 05 honda accord?

I normally just use #87, under which my car runs pretty good. However to see the difference of premium gas i added about 10 gallons #91 mixing with 5 gallons of #87 which was originally in the tank to my car. After few minutes of driving check engine light was on. Could #91 gas caused it? What should I do?

I think you probably left the gas cap loose but get the codes read, won't be the gas either way.

Check you fuel cap othewise it is coincident.

The higher octane gas is NOT a problem in that vehicle. It won't go any better with it, but it won't be causing a problem either.

A loose gas cap is possible, and easy to check. Otherwise you need to get the computer's error codes read, and work from there.

That will not cause a check engine light to go on. Maybe if there was already some problem like with a MAF sensor, and the change in gas just caused it to happen sooner?

Get the code read at an auto parts store, they usually do them for free, or you local garage.

Get your codes read. Probably just a conincidence. Accords will take any fuel.

The gas didn't cause it.Don't blame the gas.blame the light.Put an OBD scanner on it to ask the car why the light is activated.