if the maf is compatible with the system increased air flow would not cause a lean or rich condition as the maf reports the amount of air going in the motor an computer deals with it...I suspect the maf is not compatible but if it runs without the mod than the mod is causing the maf to report wrong info to computer so backup your mod its not working....maf mods usually only needed when your pulling top rpm's an the maf is restricting air flow for top hp....good luck...dan