I've got a 2005 Chevy Cobalt @ 47K miles.
At about 65 miles through a full tank of gas it started shaking at ignition and the service engine light was flashing. I immediately noticed a huge reduction in power. It can barely manage a steep incline ... but eventually (after stopping and adding 4 12oz bottles of gas treatment), I got it home. It's now day 2 - same problem. To clarify, it has not yet shown any improvement.
I also noticed the car is driving at 1k rpm higher than it usually does. It idles at normal rpm level but still shakes.
I normally get 30+ MPG. This tank is only getting 18 MPG.
Can anyone help me out here with potential problems and solutions? Thanks.
