Bad MAF?

[anziani]

The car is a '97 S500 coupe (CL500) with 136K. Have owned it for about a month. It shut down completely one day as I pulled into a exit lane off the road. Engine died and all of the instrument lights lit up. I put it in Park and it started right back up. We pulled codes from under the dash and got a bad MAF code. I was under the impression that a bad MAF would only affect the mixture, not shut the car down. We plan to clean it with CRC MAF cleaner and see what happens.
Are we on the right track, or is something else causing this?
Anziani
'97 CL500 136K
'95 E420 129K

[daddi]

Replace the crankshaft position sensor A.S.A.P they often fail like this with out leaving a code.

[Can't Know]

Originally Posted by daddi

Replace the crankshaft position sensor A.S.A.P they often fail like this with out leaving a code.

I would agree with this. It's likely the MAF code was just stored (already present) before the incident. The CPS is a known failure point and your symptoms match it perfectly. And you're right, it is exceedingly rare for a bad MAF to cause what you describe.

CPS is inexpensive and though it's a bit tight back there, this is a simple DIY. And on that engine, it's easier than doing the MAF, too.

Good luck.

[anziani]

Thanks guys. That was the first thing we changed. Today we put it on a scanner and checked all codes. The MAF did come up. The previous owner had a mechanic that used silicone to seal the valve covers. According to Jim Forgione, this is DEATH on MAF's and O2 sensors. We pulled the MAF and cleaned it with CRC MAF cleaner and reinstalled it. We drove the car and it still bucked under load but no more dieing at a stop sign. We then put it back on the scanner and re-read the codes. All codes had disappeared except some door problems. One of the senior Benz mechanics said that I should drive the car keeping it under 3000RPM for a few days for the "relearning" process. If it DOESN'T sort itself out, a new MAF is in my future (right after I put in a new fuel filter).
I'll keep you posted.
Anziani