Ecm could be bad along with or tps or iac, just off the top of my head... I have had bad ecms do the same thing with idle and bogus code scans
Built Not Bought #447, 1992 Jeep XJ Supercharged 4.7, 1988 Jeep YJ Auto 4.2L, 2008 Commander Limited HEMI, 1990 Jeep YJ 4.7L Fuel Injected AW4, 1981 Scrambler 304 Auto
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