I was reading my latest issue of TRUCKS where there was an article about diablo chip.It is an interesting read they are really having tuning issues with their 2004 f-150 .The truck has an aftermarket intake and exhaust .After they tune their programmer to the highest performance tune(93 premium) they notice air -fuel ratio going very lean with 3 error codes.I can not post the graphics but it is very clear to see how engine goes lean with the diablo.They assume the air intake kit is the problem so now they think of pumping 5 percent more fuel to recover the ratio.Did you guys experienced any problems with or without using chips assuming that you also have aftermarket air intake kit and exhaust??