Update:

For clarification, the missing electrical connector wiring refers to smog pump connector. No issues on that one.

purge switchover valve is clean and vacuum tight.

Put in CRC Mass Air flow spray into the EGR valve in front rubber nipple hose after disconnecting the metal pipe hose. Reconnected the EGR valve hose.

Cleared codes prior to driving. All codes cleared without blinking on dm button 2.

Fired up the engine. Idling around 1100 rpm. Warm up to 85c. Iding going down to 800 rpm. Pressed brake, same 800 rpm. Reverse, drive shift, same 800 rpm. Little hesitation between shifts.

Took a drive, cruise control works ok. Oil pressure hovers around between 2 and 3. Same warning lights on oil sending unit.

Stop engine. Checked the DM. Code 5 (Exhaust gas recirculation inoperative) and Code 6 (Idle speed control inoperative)


I had an extra reasonance valve intake. Did a swap of the reasonance valve intake. There are two parts to the reasonance valve intake. One is I called the flapper that goes inside the intake manifold next the throttle body. The other part is the top with the two prong male electric plugs and vacuum nipple that goes inside on the top of the flapper.

After the swap, test drive the mercedes. This time it was worse, rpm out of normal range, shifting gears long hesitation. No good.

So I took the orignal reasonance valve flapper that was performing better back on the intake manifold with the second top of the reasonance valve intake. Results were much better and less hesitation on the changing gears. It seems the top part of the original reasonance valve is faulty which was replaced by the second one. In addition, no blink codes on DM. The code reader shows no codes. Issues resolved. Thanks to everyone who read and posted comments on this thread. It had a been a long process/journey with a lot of bumps on the way. Thanks again.

P.S. I ordered the new oil sender unit, egr valve, oil pressure sensor, and fuel pressure fuel regulator. Stil have that pesky burning oil smell and smoke. That is another story.