I really hope it's not the engine, since that sucks *****. I went through the down trodden feeling back in 98 so I know the pain. If the compression is low, your not getting complete burn of the fuel mixture. Low compression is also attributable to bad gas mileage on high mileage worn out engines, same applies here. Fuel basically getting dumped out since there really is no controlled burn in a sealed environment.

Hope it's not, but a quick test will keep you from having to try and pin point something and if it's got good compression, the sickening feeling in your stomach can go away and your out 15 bucks and about 30 minutes time.

Tim