Okay finally getting dynotuned for the second attempt this weekend. just curious if my dynotuner cant get it pretty much dead on, can I have him tune for open loop. because right now with my madz28 chip it is running too lean, which in turn is dumping fuel, and surging bad. but when I unplug the 02's it runs damn near perfect. no surging/better mpg's. just curious will this still let me make the most of my power, tuning for open loop. or will I loose mpg's. and power?

new ac delco 02's only a week old. new tps/map. throwing no codes. I had my dynotuner mail me a chip last week tried it, but very rich, it did take out the surging but could really smell almost like raw fuel, so took it right back out. running on the mad. chip with 02's unhooked for now...

what do you guys think...thanks.