1995 Mercedes E320 (M104). Drivability issue under load. Starts and idles well. Low power, possible ignition miss or fuel issue. 16 pin connector, pulled codes from pin #8 and got:
35 02 rich limit, mix to lean
39 Inj short circuit cyl 2
42 inj short circuit cyl 3
47 inj short circuit cyl 6.

Oxygen sensor and CAT are new. Engine wiring harness is updated. Any suggestion on steps
To proceed with diagnosis?

Hmm not too sure. What kind of spark plugs and are they at the proper gapping?

__________________
1993 e300
1995 e320
1994 e320
2006 s500 4matic
2004 Jeep wj overland
2001 Ducati 748
2004 Honda shadow aero

get a multimeter and check/compare injector resistance

If you haven't done already, clear all the codes and start over to see which ones come back. I spent some time chasing after codes that must have been from the previous owner and had nothing to do with my issues.

I had the same issue on my '94 E320T S124/M104 (severe miss under load but fine at low power and idle) and it turned out to be one of the ignition coils; while I was in there, I replaced all three coils, the spark plugs and the plug wires. Make sure you use the correct plugs and wires.

Best Regards,
Rob

PS - I'd also be curious to know what you're using to pull those codes.

__________________
Robert Fini

'12 ML350 BlueTec, 87k
'06 E320CDI, 270k
'05 T1N Sprinter 2500/Pleasure-Way Plateau TS, 69k
'97 C36AMG, 313k (son's)
'94 E320T, 249k
'93 190E Sportline LE, 168k (daughter's)
'84 190E-2.3/5spd (Stage Rally Racer)
'66 230 W110 Sedan (Barn Find, Vintage Racer build in progress)

I pulled codes using an eBay blinking light reader. I made an error in translating codes. They where as follows:

35 air pump
39 egr switch over valve
42 can communication defective
47 control of ignition coil voltage exceeded limits

I cleared codes and idles the car for one min. Code 42 came back. Spark plug threads are covered in engine oil from leaking valve cover gasket. I’m replacing the plugs.

move to a southern state,where you don't get inspectted,and damn money racket

__________________
1999 w140, quit voting to old, and to old to fight, a god damned veteran

Instead of just letting it idle, you might want to put some miles on it to see if any additional codes return and/or go away.

I assume your cause for concern is that the Code 42 is illuminating the Check Engine Light, which would cause an inspection failure. That CAN communication failure code is specific to either the ASR module, the EA/CC/ISC module or the diagnostic module, so all I can recommend is that you try tracing out the wiring to each of the modules and see if there are any breaks, verify that the connectors are clean and tight, check that the electrical grounds are clean, etc.

With regard to the oil in the spark plug tubes, my car also suffered from this and it was a precursor to needing a head gasket replacement; hopefully, this won't be the case for you - good luck.

Best Regards,
Rob

__________________
Robert Fini

'12 ML350 BlueTec, 87k
'06 E320CDI, 270k
'05 T1N Sprinter 2500/Pleasure-Way Plateau TS, 69k
'97 C36AMG, 313k (son's)
'94 E320T, 249k
'93 190E Sportline LE, 168k (daughter's)
'84 190E-2.3/5spd (Stage Rally Racer)
'66 230 W110 Sedan (Barn Find, Vintage Racer build in progress)

Check your egr line to the intake to see if it’s clear

__________________
1993 e300
1995 e320
1994 e320
2006 s500 4matic
2004 Jeep wj overland
2001 Ducati 748
2004 Honda shadow aero

My wifes 94 wagon would throw a can communication code semi regular , I would erase the code , after a while it seemed like I had a low performing battery , as soon as the battery was replaced no more can codes its been
about 2 years and never see that code, im guesing when it sat overnight and you started it the starter was drawing most of the power and then the code would appear, it happens on newer Mercedes too, test your battery