howdidigethere

short week this week. we had the newest guy quit in fustration only to come back 5 minutes later.haha well diagnosis is kicking my ass. got this car in that they keep putting O2 sensors in and she was complaining of a missfire and of course i didnt find anything there. but the thing is rich black smoke. so i get under the hood and i pull a plug and its as black as an ace of spades. so i latch on the O2 for a signal.it shows rich but not as bad as whats commin out the tail pipe so i take my scanner and i look at some stuff the injector pulse width is 5 miliseconds.which seems alil long.MAF signal looks ok. and then i look at the O2 signal on the scanner which is totally different than what im getting at the O2 sensor it self.so something is wrong so i get out a break out box. and the signal is that same at the O2 sensor and going into the computer but the computer says its lean driving it rich. so i say well if its getting a good signal and it thinks its different well the module is bad. so we got a new one and i got the same god damn thing!!!! so i racked my brains and i got out the bible i tried to force the system lean and i got nothing i tried to force it rich. you know grounding the O2 and then powering it using my body.no effect on the system so im guessing that the its in a limp home mode and these tests will not effect the system. but then that doesnt make sense either. because limp home would put the O2 signal right down the middle but its making it dead lean with it plugged in. and then you unplug it you get limp home but the tests wont make it drive it rich or lean so now im getting at my wits end. the MAF is ok. the O2 is dead i think so we got a new one to complete tests BUT i know the cat is gone probably the rear O2 is shot to hell too. so we need to know what is making the computer read falsely lean even though the O2 says fat ......any ideas?