Okay, heres the update:

So I installed the exhaust saturday as you guy know , today as I was pulling out of the gas station the car started to jerk as it drove. The exhaust itself was basically sputtering and i have no torque or anything....At first I thought it was the exhaust with the whole donut thing and me thinking there was a leak or something... but it to a shop and they said that that couldnt be the problem....had it scanned but they don't know what the code turning up is...but they and a few other ppl i talked to think it could either be the ecu having a prob with the exhaust or its the o2 sensor....

I am looking for advice on what to do basically...

any and all suggestions would be perfect