P1391 p1392 are codes that mean rough road and performance, I had theses codes on my 96 trooper and I replaced the front brake pads cause 1 caliper was not releasing and causing drag also greased universal joints and it stopped the vibration that puzzled me to extreme . This is what I did to fix the problem I had maybe this will help you as it can be numerous of things
Trouble code P1391 means:Intermittent loss of CMP or CKP
i cant find the color code for my 1995 Isuzu trooper CD cassett please help
Trouble code P1391 means: Intermittent loss of CMP or CKP
Trouble code P1391 means: Intermittent loss of CMP or CKP
Trouble code P1391 means: Intermittent loss of CMP or CKP
Trouble code P1391 means: Intermittent loss of CMP or CKP
Trouble code P1391 means: Intermittent loss of CMP or CKP
Trouble code P1391 means: Intermittent loss of CMP or CKP
Trouble code P1391 means: Intermittent loss of CMP or CKP
Trouble code P1391 means: Intermittent loss of CMP or CKP what does cmp or ckp stand for
Trouble code P1391 means: Intermittent loss of CMP or CKP
Isuzu has a separate software system for its brake system. Usually, only dealers have it and they charge $$$ to scan it.