My car always has something wrong with it..what now?

Ok..I have a 96 pontiac firebird..v6, 3.4 cylinder. I've got a reading from the OBD-II still saying cylinder 1 misfire even after I've replaced alot of parts but my car will start, turn over and drive..it is a little rough though and stutters more when I slow down and come to a stop. I've replaced the fuel pump, the fuel filter, 2 of the O2 sensors, cleaned the fuel injectors and replaced the O rings, I've also replaced the ignition coils, the spark plugs and wires, the ignition module, and the air filter. I've also just had the compressor for my air conditioning replaced and of course the belt as well this past weekend. Although today I noticed a new issue, my car has a very sickening smell thats VERY strong, I dont know how else to describe it. but it only just happened today right after I put gas in my car, I noticed the smell on the way home. No I haven't done a compression test. what could be wrong now?