i have tested the codes on my car several times and have always come up with a code that says my car is running lean. How do u cure this? my car does have around 60-70 extra horsepower than when it was stock, is this causing the problem? will an afpr fix it?

 

when i saw the title the first thing i could think of was to try an AFPR. dont know for sure it would help, but it makes sense.
try some injector cleaner, new fuel filter, blow out the lines etc
just make sure the fuel is gettin there with no problems.