ok just test drove the car and still have backfiring and really rough idling... i am pretty sure one of the plugs or coils is the culprit b/c i also had teh air mass sensor replaced recently too. i think the water popped one of the plugs... if so would it be easy to spot which one it is so i only have to change one and what types of tools would i need. I am sort of new at this but pretty handy. wouldn't it most likely be one of the plugs in the 3 wells on the engine. also where is this water from teh exhaust coming from b/c as i looked at the engine and where the plugs and every are it seems pretty dry...