Recently my 94 E320 started running rough. I was accelerating quickly and heard a poof sound and that is when the surging and idol hunting started happening. My 20 mpg has ceased and I smell a rich gas exhaust smell. I made the 3 probe engine analyzer and researched all the codes for my M104 6 cylinder HFM/SFI gas engine. Here is what I found in my copy of CS1000, Fault Code Scanner, Mercedes-Benz Instructions, Model Years 1988-98,
Analog/Digital Fault Code Module 1988-98 OB15-11

DM in Ch 1, pin 3 codes 2, 3, 5, 7, 13, 16, & 24

2 Heated oxygen sensor faulty

3 Lambda control faulty - is Lambda control part of the O2 sensor?

5 Exhaust gas recirculation faulty - What is the metal tube called which carries the exhaust gasses for recirculation?

7 Ignition system faulty - Could this be a result of the faulty O2 sensor?

13 Unlisted here

16 Closed throttle position information faulty - Could this be a result of the faulty O2 sensor?

24 Starter ring gear segments and /or crankshaft position sensor faulty - Could this be a result of the faulty O2 sensor?

DM in Ch 8,9,10 pin 3 codes 2, 3, 5, 7, 13, 16, 24

002 Oxygen sensor. No signal (right bank in 120) - What does this mean fault or no signal in right bank in 120?

003 Fuel adaptation (lambda control), inoperative. Engine control module (right bank in 120)

005 EGR exhaust gas recirculation incorrect, fault. Engine control module (right bank in 120)

007 Ignition system defective, fault from Fuel/Ignition control system (right bank in 120)

013 Camshaft position sensor (CMP) signal, fault from Fuel/Ignition control system (right bank in 120)

016 Closed throttle position (CTP) sensor signal incorrect/implausible.

024 Crankshaft position sensor (CKP) signal incorrect or starter ring gear segment damaged.

EA/.CC/ISC pin 14

5 Stop lamp switch (S9/1)

11 Closed throttle recognition signal to engine control module (HFM-SFI)
Fuel safety shut-off to engine control module (HFM-SFI)

HFM/SFI pin 8 codes 4, 5, 9, 13

4 Hot film mass air flow sensor

5 CTP switch

9 O2S 1 (before TWC) - voltage too high, circuit open or voltage implausible

13 O2S (Lambda) control system operating at rich or lean limit

HFM/SFI pin 8 codes 4, 5, 9, 13

004 (006) Intake air temperature sensor, short circuit

005 (007) Intake air temperature sensor, open circuit

009 Not used

013 (015) Throttle valve potentiometer actual value too low

Any suggestions on where I should begin and how I should proceed will be greatly appreciated as I am on a limited income and don't mind doing some dirty work. If anyone knows of some other sources of good used parts please let me know.

I think the first thing I need to do is get the o2 sensor squared away. I have to wait until the first of the month for funds to do this. I also want to clean the exhaust/emission metal tube that runs from right to left across the engine in the back. I can do that job with out any cash so I am looking for some instructions on doing it. I wish I knew what the emissions part is called.