I have been doing a lot of reading since about tuning and understand now how the 02 sensors try to keep the a/f ratio at 14.64:1. The thing is i have some friends that dont think 02's are needed and are not running them. My question is by taking out your 02's what does it make the computer do. When it doesn't get a signal from them. They also do not run egr or any smog equipment. Without any tuning. The cars are foxes running a9l computers and haev h/c/i and most bolt ons. I was trying to explain it from them with my knowledge about what 02's do and why you have to have egr turned off in the computer. Just wondering if someone could explain that stuff to me a little better and what the computer does if it just stops getting signals from them.