92 92 500 SEL Help with intermittent miss/stumble

[charjac]

I have a 92 500SEL 140.051. The car runs reallygreat, with the exception of a slight and intermittent miss/stumble at idle. The car never comes close to wanting to stall just a slight stumble that annoys me. The motor will shake a little and the RPM will drop slightly for a second but not even close to a stall. Same condition in P-N- or D. It can go days without it happening and then start again. 99% of the time it will go away with a restart and usually takes a day or two to come back. I get good to great fuel economy -17-20 MPG and don't drive like a grandmother. I have never had a problem above idle. I have searched every post for weeks and the only thing I found I have not done is a fuel pressure regulator

What I have done
3 tanks of Shell Vpower and Techron cleaner
Fuel filters
Wires
Plugs
Caps & Rotors
Clean MAF 2x as per directions on the uberallies site. The boot for the maf does have a slight crack at the bottom where the hose clamp goes but I sprayed it with carb cleaner and it did not suck it in.
Cant find a Vacuum leak. I sprayed multiple cans of carb cleaner around every hose I can find with no difference
Checked every connection I can find (I believe the harness was changed as all insulation is brightly colored and soft and pliable)
Injectors all "click"
Cleaned coil contacts
At the suggestion of someone on this forum I built a code reader. I made a photo DIY PDF with part numbers but is is too big to attach. If anyone wants it let me know and I will email it to you.

I read the codes and cleared them drove the last week about 200 miles and re-read.

I pulled these codes and the results below are from the baum guide. I don't really understand where to go next.

Pg 29 LH Sequential Multiport Fuel Injection Socket 4 No codes
Pg 34 Base Module Socket 8 No codes
Pg 45 Distributor Ignition Socket 17 No codes

Pg 35 Diagnostic Module Socket 19
code 6 Idle speed control faulty
Code 17 Data exchange fault between individual control module
Code 19 Injector open or short circuit or emission control adaptation at limit

Pg 48 Electronic Accelerator/Cruise Control/Idle Speed Control(EA/CC/ISC)w/ASR Socket 7

Code 2 EA/CC/ISC control module (N4/1) or Safety contact switch (M16/1s1) or stop lamp switch or cruise control switch or Actual valve potentiometer or starter lock out/back up lamp switch or engine speed signal or vehicle speed signal or closed throttle position switch or safety relay in in EA/CC/ISC control module
Code 3 Right EA/CC/ISC actuator (left cylinder bank) (M16/1)
Code 6 Starter lock out/backup lamp switch
Code 14 Closed throttle position contact switch

Any insight appreciated. I have very little hair left to pull out.

[mbdoc]

The codes in the EA computer are the most likely cause.

That system needs a lot of info to operate correctly.
The safety neutral switch on the trans is a common cause of that type of issue.

Also cleaning the throttle butterfly is important.

[charjac]

Thanks for the info Doc

The codes in the EA computer are the most likely cause.
That system needs a lot of info to operate correctly.
The safety neutral switch on the trans is a common cause of that type of issue.

Also cleaning the throttle butterfly is important.

I would say I darn near polished that butterfly last month when I was cleaning the MAF for the second or third time. Would you think clearing every code and replacing the neutral switch is a good place to start?

Thanks again