C220 Ignition Coils repair

[illini32]

I need some help reparing my 1995 C220. Problem is the car will idle
rough after driving for over 45 minutes. It will idle rough and misfire until
you stop and restart the car. I had my mechanic hook the computer up
and he says getting a misfire code and some o2 codes. He said since I have
new spark plugs its likey one or two bad ignition coils for $100 a piece.
he would likely charge an hour of labor at $95.

My goal is to not spend more than $300 and fix this problem.
I would hate to pay $300 for the coils and then still have to get the mass error sensor. As that sensor is expensive $300.

Question: Is it possible for him to replace each coil one at time and see if
the error code goes away? Then would only need to replace a coil if it is bad

Question: If the mass air flow sensor is bad, would the diagnostic computer display a specific error code? Or would it display general o2 errror codes like
I have currently.

Note: I put a new wiring harness in a couple years ago. So that should be good.

Thanks in advance!!!
Cheers, Mark

[illini32]

Mass Air Flow Sensor I meant.

[illini32]

FYI, I also had a second mechanic do a diagnostics check and tell me I needed ignition coils. Of course they wanted to replace of them for $400.

[illini32]

Just spoke with my mechanic he said:

It could very well be a mass air flow sensor. or it could be wiring or a coil.

He said bring the car in when its misfiring and we can tell which ignition coil
is bad. Fix that and see if that fixes it. Seems like a reasonable place to start.

[deanyel]

You're hogging your own thread here. You should be able to read the codes yourself on the 38 pin connector, swap the coils yourself and see if the fault codes move with the coils. You have two coils, should be about $75-$80 each on the internet, and should be easy to replace.

[MarcusF]

If you have multiple coils, one approach may be to swap them and see if the miss follows the bad coil.

[Rashoood]

it append with a freind of mine in his CLK 320
he changed the air flow sensor and the car has changed totally