Dirty MAF.
Vacuum leak.
Hmmm. Probably.
I tried cleaning it, tried replacing it. same result. lt ftrm1 -1.6 st ftrm1 -23.4 lt ftrm2 17.2 st ftrm -23.4 this part of the reading I got makes me wonder why the lt ftrm2 is high? I've tried researching it but so far havent found any info.
Check for a vacuum link related to the PCV system. They are prone to cracking and clogging with age. Pay particular attention to the elbow located near the throttle body. It is probably best to go ahead and replace all of the soft parts in the PCV system as they are difficult to clean once they began to clog. It is possible to clean the metal parts.
Lugnut
You should be finding out why bank 1 fuel trim is minus 25
fuel pressure reg. maybe? it has had pcm replaced with a junkyard unit about a year ago, any chance it could have same issue with this one? It will run, although very bad with the maf unplugged, as soon as I plug it back in it starts to run rough, very rich (black smoke and lots of it) and misses badly then cuts off. I tried a new maf and no difference. Any good ideas would be appreciated. Chrisntrouble
Maybe IAC valve, maybe vacuum leak. See:
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