CEL problems 1998 e300, intermittant CEL

[92497pmu]

Back again after lots of (soul) searching why my e300 doesn't always love me.

I had a check engine light (CEL) come on last weekend on a steep hill start. It tripped the turbo wastegate, hence no power = sorry benz.

After plugging in my OBDII I had 3 codes. Cleared them. CEL P0100 Mass Air Flow problem. Bought a new one from Phil. CEL goes away after 10 miles of stop and go driving. Same result as 3 years ago when the MAF failed.

New problem (well, not new, but back again and has been intermittant for 3-4 years)

Scenario:
Driving down a long grade coasting into toll booths (I love NY), accelerate away - CEL and lots of codes. Usually goes away after a shutdown/ restart or 100 miles of driving.

Symptom:
No power, CEL
No visible fuel leaks. No injector pump problem. No delivery valve issues.
Today I happend to have the computer & OBDII

Codes
P0100 - MAF
P0400 - Exhaust gas recirculation
P0243 - Turbo/Super Charger Wastegate Solenoid "A"

All codes seem to make sense, no air, bad exhaust, Benz computer dumps the wastegate and the car drives in non-turbo mode like a 4000 pound lazy pig until I reset.

I've searched some on this but haven't found anyone with a similar set of codes/ problems. Car has been reset. Just drove 100 miles, no problems. I know it will do the same thing on the hill up to my dad's farm 10 miles from here.

Any takers?

I'm unfamiliar with the P0243 problem and where to find this solenoid in the car.
I've heard of a K40 relay that has something to do with fuel, air, computers and lots of other stuff. Not sure where to find this one either or how to test.

Thanks & happy Easter to everyone.

Phil

[TMAllison]

You know hat PO100 is; not clear if you bought a new MAF and repalced it this time, or if that was last time? It takes ~50 miles driving for the ECU to adapt itself to the new MAF.

PO243 is tripped by the vacuum transducer controlling teh wastegate. PM me your email address and I'll send you the electrical and vacuum tests to determine if it is a bad transducer, your ECU or the vacuum pump at fault.

I don't have the vacuum transducer test for the EGR PO400 transducer but suspect they are similar (using diff ECU pins) as are performed for PO243.