I got a problem with my wife's Monte (01 SS w 3800 series 2) car cranks over but stalls almost immediately. Blows some black smoke as well.... Took it in to the shop and they said Cat AGAIN.... Well it was just replaced 8 months ago (still under warranty)... So, they replace the Cat, call us and my wife went to pick it up and it did the same thing !.. Cranks over, starts for a second, then stalls... Over n over... Well, they took it back into the shop and called us and said it was a MAF sensor and would cost $225 (for a "remanufactured one") plus a core charge of $75 and about $40 labor to replace it.. I call BS On this... We had to pay $65 for the labor to replace the cat, now this ? Sounds like a rip to me ( the price that is). HELP, can it be the MAF, or the MAP ???? And the cost of just the MAF for that ? Autozone sells them for $45! Brand new... Thanks guys...

MITCH ?...lol... Give me a shout buddy....

 

To test the MAF....

Unplug the MAF.... Start the car....If it drives problem free... Then you have a bad MAF.... I also call BS on that price... its something you can change yourself in less than 5 minutes!(The MAF)
Besure to buy a AC Delco.....(Standard GM replacement)
dont buy an "OFF" brand. your only asking for trouble down the road.
Ive never heard of a "Core" charge either!

Mine acted the same way when my MAF went...
Mines also a 3800 series II.

 

You're not getting a new MAF for 45 bucks.

But yes, you unplug the MAF and if it stays running instead of cutting off, you've got a bad MAF.

Check your grounds, ICM, and crank sensor if the MAF is not the culprit.

 

I am sensing some BS in this too. I come from a school of thought that I may have to pay for parts, but if you (the professional) incorrectly diagnosed the problem, I understand time is money, but you need to either wash your mistake or cut me a discount for your error. But that can be a dead end argument and a whole other topic.

For the CAT issue, I don't know many ways of testing a cat, but I've heard a quick/cheap test is removing the upstream O@ and letting exhaust breath out that port for a short time to see if a change it found. Or, depending on the exhaust, separating the cat from the down pipe or down pipe from the rear mani (letting the exhaust breath unrestricted).

The big thing to me is the black smoke is in indicator it's dumping too much fuel. Next question is "why". By the sounds of things, this shop is not diagnosing, they are throwing parts at it.

First thing is first, if the car is stalling out, it should have a code in the computer (it may not trip the CEL yet, but a good scan tool can check "last code thrown" despite if it trigger the light or not). Another step is again, a good scan tool (like a shop should have) should be able to record some sensor data and allow a tech to check it frame-by-frame (I've done this with a Snap-On scan tool many a time). In that they should be able to check some numbers out (for me, the non-professional, I need to compare those numbers to an identical car for them to mean anything).

As mentioned, disconnecting the MAF is a good DIY check for the problem. The PCM will substitute missing MAF data to allow the engine to run. If the car runs, problem found, if not, keep looking. I have dealt with a failed MAF on the L36 before resulting in random stumbling and stalling. But never smoke.

But at this point, if they claim it's the MAF, as said, you can DIY this one. Also, get another AC Delco MAF, I've read stories on multiple 3800-based forums the none AC ones fail shortly after warranty.

Below is a screen shot of MAF prices from RockAuto (bottom 2 are AC Delcos). You will notice the high price for AC and a couple with core charges.

 

You have a N/A 3800 right? ****, I think I have like 8 MAF's around, and the junkyards are full of them. Not worth spending all that money on such a cheap part.

 

Hi, I put the price of the MAP sensor by mistake, the MAF sensor is $118.99. My bad, although it's more, by no chance is it as much as these idiots want to charge.... Thanks...mjclemm..

 

Thanks for the reply guys... Helped out a TON !... So, this is where I am at.... We called to "Garage" and told them not to do anymore work to the car. We went to the "Garage" and picked up the key. They wanted to charge us $65 labor for changing the Cat that was under warranty (normally I wouldn't mind, I understand you need to pay labor even for a warranty part replacement) HOWEVER, we didn't have a bad CAT to begin with, it was there mistake for the misdiagnosis, not mine. They replaced a GOOD CAT, not a bad one, so I didn't pay them for that. I DID however pay the a "fee" for the diagnostic and time they "worked" on the car (they wanted to still charge me to change the MAF as well as the cat...), I felt that $35 was more then fair because of THIER mistakes. After I got the keys, I opened the hood, disconnected the MAF sensor and drove it home. Then to make sure it was the MAF and not more sensors or whatever, I took the MAF sensor from My Black Monte SS and put it in the Wife's Monte... Ran like brand new, so with all the help from this site, it saved me a ton from a "Dishonest Mechanic". Now, I went and picked up a AC Delco and put it in mine and I'm ALL SET.. Thanks again for all the information, things to try, and the help diagnosing the REAL problem, you guys nailed it!.. I much appreciate all the help.. You guys are the best......... Thanks again..Michael.....

 

Your very welcome Michael!
Thats why were here at the MCF and good to know you didnt let that place Drain your Wallet!
Thanks for being a part of the MCF Family!

 

Glad you got it taken care of.

 

Glad to hear your problem got fixed, gotta watch these crooks out here