i think my 2003 cadillac cts is not responding very well and the exceleration is not that quick in other words it sucks

.
a wile back when i was trying to fix the airbag light that was always ON i was told by one of the dealers to unplug the negative on the battery for about 30 seconds and and plug it back and leave the car running for about 2-3 minutes and that should fix the airbag but ever since that i'v noticed that its not as quick the proformance stinks....
i dont get any codes and the DIC....
any suggestions appriciated
thanks in advance
Marcel