Help us help you. By posting the year, make, model and engine near the beginning of your help request, followed by the symptoms (no start, high idle, misfire etc.) Along with any prevalent Diagnostic Trouble Codes, aka DTCs, other forum members will be able to help you get to a solution more quickly and easily!
just for reference I don't know if you read all the posts but the problem has always been po175 po172. I've noticed through all the old freeze frames that it only happens either at idle or when coasting at low RPMs. I'm bringing it to a mechanic that did the relearn that failed that caused this issue on Tuesday.