Has anyone tried switching out the 02 sensors and remapping the computer to get more gas flow. I spoke to my mechanic and he said this would add a lot more hp and he would not need to changeout the fuel rails or injectors. Has anyone tried this mod as I have a 2002 with a cold air intake and fabspeed exhaust. The cost is about $800 for what he claims is a 20%+ hp gain.

 

Honestly, you're on a fool's errand if you think pushing more fuel is going to squeeze this much power out of the stock M96 engine. IMHO, I wouldn't do it, we already know that fuel leak down and injector issues lead to washing of the cylinders which in turn promotes cylinder bore scoring. Enjoy the car for what it is and if you need more power, then move to a Mezger based Turbo. Money well spent!