JohnKoaWood

I had an issue with my car recently, after doing major turbo maintenance, my MAF and In line MAF translator are en route back to vendor to troubleshooting / replacement as car on start was running HORIBLY rough..spewing black smoke... 9:1 AFR, MAF was outputing 4.8VDC at idle... tap on computer, MAF output dropped to .8VDC car ran like a swiss watch..took for drive, ran horrible on boost... now MAF voltage wasn't climbing with airflow... tap on computer... jumped to 1.6VDC, more taps..2.5V..few more taps 4.8V car run rough again... pulled MAF and computer and contacted vendor...he is going to check both components on a known good car and tell me which one needs replaced...

check your MAF / AFM for proper function... sounds like you are running very rich, and maybe #3 injector isn't firing...3 and 4 are tied together so DME is rulled out, injector or harness is suspect, as is MAF / AFM...