I have tried just about everything. car goes into closed loop and immediately goes to 1100 as far as scan readings. May flucuate a little by revvving it up some but never less than 99x. Originally it would not go into closed loop but come to the conclusion that a portion of the ecm must be damaged, replaced with backup ecm and replaced o2 sensor. Using same program as before I started having these issues,car started went into closed loop(ran crappy) and started hitting the 1100 range as far as reading. btw at the begginning I did get a code 13 which of course I replaced the o2. Ihave pulled the vacuum line off of the fuel regulator think maybe it was defective,allowing too much fuel,replaced o2 sensor again, and checked for vaccuum leaks.
Also if this is a factor at all had issues with tunercat and went back to demo version 1.73 and possibly not using a compatable library to tune with . Now have the newest version along with I think the newest library(10.3). but still the same thing too rich. Any ideas ???!!! BTW I also lowered the battery vs inj. pulse,first maf tables(lowered) and raised injector flow rate all to get it to be leaner. any help would be appreciated

And the plot thickens!!!! I just replaced the computer and now no closed loop which happens to be the original problem in the first place!!!!!voltage for o2 stays almost dead on 453!! It is showing cross counts thou. any one ???

MAF might be taking a dump on you. Maybe burn-off relay also (it cleans the MAF at key off).

Try disconnecting the MAF connector. If it's better, then it might be a good indication of a MAF problem (but with a modified engine, it might not be as accurate of a test as with a stocker).

thanks for the response!!! would that force it into closed loop???? runs good in open but no closed loop. Is it possible for the ecm to have picked up a virus from the scanner?? I ask because I use to plug it in and not see a change in the motor, but now I do.Because the motor is modified I have the maf setting for error a little high.