VY SS Lean on fuel

[MRSVYSS]

I have a 2003 series II VY SS. I recently had my car serviced by my mechanic and the next day my check engine light came on. I took the car back to my mechanic as i have never had a problem with the car before i had it serviced let alone the check engine light display on the dash. My mechanic plugged his machine to get the error code and it came back as lean on fuel. He said it was prob my oxygen sensor playing up. The next day i drove the car to work and it kept stalling on me and the check engine light kept coming on. I work across the road from holden so made it to holden so they could check over it and went to work. Holden told me that because i have an after market exhaust they can sometimes set the sensors off. I had the exhaust fitted to my car 12 months before the check engine light had started coming on and as i said it was fine till i got the car serviced.
Since i have been having the issues with the check engine light the car is a pain to start in the mornings it sounds real rough and stalls till i give it a good rev, i warm my car up 15 mins before i drive it and it does not run right till it is at normal temp. I have noticed i am going through more fuel then normal and the car feels like it has lost some power. I only use premium petrol in the car. Can anyone suggest what they think may be wrong with the car or what i should have checked? Has anyone else had simular issues?

[Jezza]

have you have the oxygen sensors replaced?

[wikky]

Sitting in your driveway doing burnouts and you wonder why you have problems with your car....

[MRSVYSS]

hahahahahaha no i had this problem before the burn out! no i will get the oxygen sensors checked thanks mate.