I just had a complete fuel system tune up on my 2003 Sable. The car ran great for a week, now there is no foward or reverse and water is coming from the exhaust. Is the work that was done possibly related to this problem?
No
Water in the tailpipe is probably condensation in the pipe. No forward or reverse is you transmission which has nothing to do with the fuel system.
Complete fuel system tuneup??
It sounds like a headgasket or intake manifold gasket let loose, and the transmission has also gone south. Do you have any diagnoses yet?