i have a 94 ssei. I bought it a few weeks ago, and it ran fine. but now it started dumping a **** load of gas. I filled the car up twice when it ran good and got around 330 to 350 miles on the full tanks both times, but it started running bad and i only got about 80 miles on this last fill up. it idle'* ruff and wants to die but doesnt, and when i take off its like its missing and pauses before taking off and at low rpms it feels like its missing, but above about 3500 rpm it runs fine i know a tune up might help the missing but what about the 80 mile on a full tank, thats what has me confused. I just put 10 bucks in and only got about 6 miles???????? now my brother did take the srceen out of the maf sensor with out telling me cause he thinks it will have the same effect as it does on my camaro, by adding abot 6 hp, but i think hes wrong. I just dont know that much about the 3800 supercharged, it has alot of vacume lines, and fuel line'*, any help would be great so i dont have to take it somewhere, thank you.

With mileage that bad, I would be looking for a gas leak.

i already did that its running really rich, you can smell it, i dont get it. is there any sensor or something that would make it run that rich and just dump fuel like that?

If you don't know how old your O2 senosr is, or if you KNOW it'* 50k or older, change it. It'* located in the rear exhaust manifold sticking straight up. Looks like a spark plug.

The next most likely culprit is plugs and wires or a coil. Coil pack troubleshooting is in Techinfo. Plugs can be visibly inspected, and wires can be checked with an ohm-meter or multi-meter. If you check them, report your numbers here. If you inspect your plugs, post a closeup pic of them here (keep them in order).

After checking plug wires for resistance, put them back and spray a light mist of tap water from a windex sprayer on them at night with as little ambient light as possible. Look for arcs and sparks.