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Re: 2000 GMC 7.4L Emissions
Posted to HD/Fleet Forum on 12/20/2006

Hi Sam, Well since it's running fat I would make sure the O2 heaters are working and the ECT is at least 195 at idle. If the outside ambient temp is cold and the ECT is borderline, it might be falling into open loop. What is the LTFT and STFT? If it is subtrac... Login to read more.