Quote Originally Posted by BillBoost37 View Post
The only "chip" that comes off ebay typically is a resistor that goes in line with the IAT to fool the pcm into dumping more fuel. Which..the O2 then adjusts back out once it sees the fueling as pig rich.
Actually, it does not do that. It MAY increase your timing, but even that is unlikely.

If you were to disable the maf sensor and go into VE mode, you would get alot more fuel (like, up to 12-16% extra), and you would not have the o2 sensor pull it back out as closed loop does not function in VE mode. So it is somewhat true in that sense.