I replaced my MASS last month - 1) it has not adjusted the computer after 3 weeks or. 2) Has not cured my problem because it is defective.3) its not my problem.

I keep getting codes suggesting the MAS.

There is an Ebay seller that says he is a Mercedes Tech and sells used ones that are tested and referbished.
I asked him if referbished means "cleaned". He wrote he has a process where he brings them back to specifications. I asked him again, " So you clean them ? " He did not reply to my 2nd question.

I may have wasted some more money ordering a tested used one..should be here this week.
I have analog and digital electric test meters. Anyone know what to check on a MAS ?

Last week I checked my ignition wires on one bank but still do not know what specification they should be . if anyone knows that would help me rule out the wires. Replaced plugs two times in 10,000 miles and new cats.

Not hitting on 6 in Michigan.
steve

__________________
Steve Danville
what i did myself.
CPS
rear shocks
MAS x 3.
SparkPlugs (twice)
Fuel pump & Filter
Window switch
replaced both failed horns with Honda horns.
Cleaned ERG Tube
Oil changes
Oil consumption Fix
Brake Pads
A/C Recharge
Anti-Freeze change X 2.
Front Shocks. Monroe. $90
Mercedes Warrenty Work:
Harmonic balancer,power steering clamp. Cat converters.Drive Shaft Bearing.s
Replaced Outer Lower Tie Rods and front lower ball joints at 156,000 miles