2004 3.8 SS non SC 140k mls. Monte Carlo
 

Hey all, Thanks for letting be here and share my headache. I bought this MC used with 130k on it and in excellent condition. At the 140k mark after months of playing with its quik power and just fun to be in, I found a 1/4 miles decent straight to test her out. I quickly got to 105-110 and very please. I back off getting close to end of road and something happened after I parked it that night. The next morning I started it as normally I do and there was a terrible miss. She wants to die at stops, rattle like hell taking off, terrible muffler noise, no power on the street at all just clips of power as it kicks in and wants to run but its like starving. Now, from that point to now I have been out a lot of money and a lot of lessons dealing with auto part house. I know now they are in it to make money not fix the problem. I have a code reader and it showed, he said, my mass air flow was bad. I replaced it, it made it worse. He said try the idle control valve. didnt help. EGR, didn't help. Had the coil pack and brain checked, nothing, Fuel filter, pump, catylac converter checked out, plugs, wires, and anything else now would just be quessing. I have tried 4 different shops and they all want $250 just to hook it to their new high dollar machines and then hit and miss they said on their end too. OK, I am disabled and dont have the money to do much more hit and miss and them on a hourly wage. Ive ran heet through it, the guarenteed stuff through it. She starts fine and idles OK until she worms up then she drops off the 1000rpm to a little over 500rpm and then tries to die, barks and climbs back to 1200-1500 rpm. and its just terrible. God if I tore it up by just getting on it one time what good is is. I watch cop chases on TV chasing a beater and I envy it, thats how bad it is. An SS without power, rattles and 78 Fairlanes and Granadas are passing me, not good. So thats where I am at and I hope youve had this same issue and can help me. Thank you

Ive had MAF sensors that when installed into the car new, ran worse than the one I had just replaced.. Try unplugging it altogether. If it runs better, its the MAF.

Ive also had a bad IAC cause similar issues.

If you run out of options there is always the ODB2 plug bluetooth phone thing.. Hook it up and start analyzing data..

Id try unplugging the MAF first tho..

Last straw
 

This is my 1st v-6 and its about to get the **** kicked out of it. I hate all this **** they have plugged into these cars now. I am 57 and my other MC were not a pain in the ass. BUT I love the feel and when its in its game, shes good, but this town has nothing but dumbasses working here so I have to try to find the problem myself. I unplugged the Mass Air flow, idle conrol & the one below it and it didnt change anything. still ran the same without all three unplugged. So I unplugged the one on top left and she died. turned on the AC and she damn near died, Goes from 1000rpm to 400 and even without the 3 being hooked up it recovers without dying. Could the converter cause all of this. Its not like the old days, $9.99 got you about any part. Now its $150 or better and if you install it, its mine. Up at Oreilly, put the tester on it........its the MAF, so i bought it, he's still standing there, it run worse and I said refund this, aint it.......so, I seen you install it. YOU TOLD me I needed it. Anyway, same with all the rest and bottom line when i put it in drive she growls, really rough. Yesterday I got it to 80mph no problem, it just wont low speed