Ok so here's the deal we have a 2004 Grand Prix GTP that ran perfect when we got it, we'll it started acting up and they (it's my sisters car) took literally like 6 months or so to get the proper plugs for it which stopped the horrible misfire but the deal is that the car still doesn't seem to have the power that it used to and we reset the computer codes using the battery but the CEL is still on just no longer flashing, the car has a lot of power as it is but I'm thinking that maybe the CATS are plugged? We tried reading the codes but it never has let us it loads and then gives a loading error.
Sent from my SPH-L720T using Tapatalk
