Is your AFR reading or is it stuck at 14.7 and the exhaust smells and looks pig rich?
I had this happen to me twice and the way I fixed it was I disconnected the battery, shorted the positive and negative cables together (I used a jumper cable) for about 10 minutes. When I reconnected the battery and started it the AFR was back to reading normally and it didn't smell it look rich. Hopefully this will help.
