Just started it up after winter and is running horrible. Spitting and sputtering, lower idle than normal. Still runs and starts fine, just misses pretty bad and sounds horrible. I suspected bad gas and ran a tank with seafoam then half a tank with techron cleaner. That didn't do the trick so i changed the plugs and wires to no avail and then the air cleaner which i think made it worse. I have a thundermax tuner and don't want to take it to the dealership as they won't service with that tuner. Any ideas on other things i can eliminate?

Thanks in advance everyone.

 

Check for leaks in your intake manifold.

 

Critters get into something, maybe chewed up some wiring?