Recently my 1999 3.1L is running rough. The code shows #1 misfire. I have changed the plugs and wires. Plug wire #1 was checked and it has a spark. I pulled the #1 plug out and it seems wet. After I reinstall the plug and clear the code, the engine seems to run smooth. after it warms up, it starts to miss again, especially noticed when you put it in drive. Also, the exhaust smeels bad (almost like brakepad on rotor when you hit the brakes hard). You can also here the miss in the exhaust pipe. Can it be a bad injector stuck open dumping excessive gas into the cylinder or maybe a plugged catalytic converter. I also noticed that the coolant level was down and the thermastat needs to be replaced since it takes about 8 minutes to get heat. Also, I did replace the intake gaskets with the new improved gaskets about 60K miles ago.Any information would be much appreciated and thanks in advance.