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View Full Version : Lean COS5 startup, tune and log included



smokeysbandit
September 20th, 2008, 03:51 AM
Hey guys, after having tuned a bunch of cars, including my own I figured it was time to try out the custom operating systems. Now my current problem is that at cold startup my tune goes extremely lean, off the wb kinda lean. I have tried a number of different things, and am sure I am missing something simple, and have read that cos5 does not have the lean problem cos3 had when it first came about. You'll see in the log that the car starts and is very lean, even though the commanded fuel is at a reasonably rich level. After sitting and idling up to temp the commanded afr and wb afr miraculously begin to coincide. The car is a 2000 Trans Am with an LS6 intake, and a 224 cam. If the tune looks a little lean its because I now have the wideband post cat. Help!!
Thanks,
Brandon :cheers: