They are 2.00 at a junkyard. If you can put your finger over it and it runs fine then that means it is obviously leakign vacuum. The engine is running rich because the excess vacuum is causing it to run lean and the computer is compensating. Its not misfiring in a cylinder, its just flat running like crap. Plug the vacuum hole and unplug your maf. It will most likely run the same way. You need to put that ball back on. The deal with the snow drift is most likely is sucks in the snow, melts it to water and that could be causing a misfire. I bet you put that ball back on and it will run even bette than it does now. DOes it stall once in a while sitting at a stop
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