I just bought a 2002 maxima and I had fuel injector #4 replaced and put teckron in the gas tank. I took it to a mechanic and had those things done however before I took it there it never smoked that bad. The smoke had a little bit of a gas smell and it is white. The more I gas and go the more smoke that comes out. The car has 180,000 miles on it. PLEASE HELP

Make sure the car is not overheating and using coolant. White smoke often accompanies a leaking head gasket, where coolant is leaking into the combustion chamber and being burned. You may want to check the compression, and how it builds, on each cylinder. It can tell you a lot.