I got the codes pulled from autozone and it gave me

p1128

I looked it up in the haynes manual and it tells me that the
"Long Term Fuel Trim too Lean(Bank 1)"

As far as i know there are no engine mods to the car. Does anyone have any idea what would give me this code or how i would go about fixing it.

 

Try cleaning the maf sensor. Most rich/lean coditions are caused by the maf sensor. Is that the only code?

 

Most likely cause is failing oxygen sensor. Failing that clean your injectors (I'd do this first with Techron injector cleaner as this is the cheapest thing to do).

Other causes are low fuel pressure.

If your car has close to 100K miles, it is probably time for a new oxygen sensor anyway.