Problems with honda engine?

I got an 01 Integra with a B18B1 in it and the other day I got gas in it and went home. Shut it off and then started it again to go back out about an hour later and the engine seems like its shaking back and forth, and the check engine light starts flashing. I thought it was the transmission mount so I replaced that since it was about to fall apart anyways but that didn't even work. Does anyone know what might be the problem? Does anyone think it could be bad gas?

Could be a faulty throttle position sensor, o2 sensor, etc. Best thing is to bring it to a mechanic and get the error code checked, they will be able to tell you exactly which part is faulty.

There really is no such thing as bad gas. It sounds to me like you might have a misfire which would explain the check engine light. But what would cause the misfire is hard to tell there could be a million things that could cause it. It could also be the engine mount but that would not usually cause the engine light to go on. So yeah I think it's a misfire.