I've discovered a pattern...possibly.
 

Hello again fellow MB owners and enthusiasts. Here’s another installment of my ongoing Forum series ‘Why Won’t it FRIKIN RUN RIGHT”?! So I was on FCP Euro about to order more parts to throw into the pit, when I suddenly realized there was a pattern with the car. When I first purchased it, it ran fine. No problems, no CEL, no codes, and it ran smooth and strong. Then, after about 70 miles or so, got the CEL, and a rough idle. So I parked it in the garage and fired it up a few days later (definitely not a daily driver), and it would be as if it never had a problem. Smooth idle, no CEL, no codes. But then, after a number of days and a few short trips around town, it will revert back to having the rough idle, CEL, misfires, and O2 sensor codes. So it seems as though every few days/weeks or so (or after a certain number of drive cycles if you will), the machine will go back and for the between running fine, to acting a damn fool. So the question now becomes, what might be the cause of this type of intermittent Issue? The only constant in this scenario is that the codes are almost always of the O2 sensor / engine misfire variety. I replaced the O2 sensors when I first started getting errors, and the next thing to do is a smoke test to eliminate (or confirm) a vacuum leak. But other than that, I’m out of bullets.

So, as always, I’ll greatly appreciate any and all information anyone may have. Information is power, so thanks in advance!!

Have you replaced any other sensors? I would throw parts at it, most of these are not big dollar items:

crank position
cam position
cam magnets/servos
intake air temp
coolant temp
mass air

ignition system: coils, wires/boots and plugs

I'd look at the information you've got before spending any additional money on parts. What specific codes are you seeing?

Are the O2 sensor codes indicating a lean or rich condition (low voltage code = lean, high voltage code = rich)?

Are you seeing misfire codes on any specific cylinders?

maybe simply electrical wiring problem between sensors and engine module, bad engine module, corossion
did you check that
do you keep records of the fault codes ?

Thanks for the info guys. I actually ordered ordered new plugs, Camshaft Position Sensors, Camshaft Adjuster Magnets and Camshaft Adjuster Magnet Harness Kit a little while ago and will be installing all these items this weekend. We'll see what happens after that. But some of the codes I've gotten are as follows, and this is from the most recent scan:

P0607, P064D, P064E: "The electronic analysis system for the 02 sensor in the engine control module is defective". (which is a bit concerning).
P2237: "G3/4 Right 02 sensor, before TWC [KAT]: Voltage is too high".
P2240: "G3/4 Left 02 sensor, before TWC [KAT]: Voltage is too high".
P0030: "Heating of component G3/4 (Right 02 sensor, before TWC [KAT]: Open Circuit.
P0050: "Heating of component G3/4 (Left 02 sensor, before TWC [KAT]: Open Circuit.
P0300: "Misfiring".
P0305: Misfiring of Cylinder 5: Damages TWC (P0305)
P0307: Misfiring of Cylinder 7: Damages TWC (P0307)

So as you can see, they all seem to be 02 and misfiring type errors. And I've gotten different cylinder misfires on different scans. I'll be installing the new parts this weekend and will report the outcome thereafter. But any additional details on any of these codes will be greatly appreciated.

THANKS!

that is what I suspected, engine module
start by opening it up and look for corrosion

Ok cool, I'll add that to the list of things to check this weekend.

Have you done a detailed inspection for oil contamination in the harness? This is well documented on this site. It seems to affect engines in the early 2010s until the mid 20teens, but this is a guess based on posts from this site. Pull the connectors off the sources (below) and use a bright light to inspect.

Oil emanates from failed cam position sensor and cam magnet housings and migrates to the ECU causing CEL and misfire. Some posters have reported contamination at the O2 sensor, where the oil must have travelled.

Ok folks. I spent the weekend replacing the Camshaft Position Sensors, Camshaft Adjuster Magnets and Camshaft Adjuster Magnet Harness as well as all new spark plugs. The car fired up and ran smooth for few, but soon reverted back to a very rough idle, CEL and a misfire or two. I cleared the codes and scanned again, and once, I got a "P0410 malfunction of secondary air injection at left bank of cylinders" error, but scanned again and that particular one didn't return. What did return was basically a variant of the same errors from before.

P2176: Throttle valve actuator. The throttle value is jamming or is stiff. (got this one before, but it comes back even after you 'teach' it)
P0300: Misfiring
P0305: Misfiring of cylinder 5: Damages TWC
P0307: Misfiring of cylinder 7: Damages TWC
P0030: Heating of component G3/4 Right 02 sensor before TWC. Open circuit.
P0050: Heating of component G3/ Left 02 sensor before TWC. Open circuit.

I'm gonna let the car chill for a few and I'm gonna scan it again later today. But misfiring and 02 sensors still seem to be an issue. I was hoping for a definitive answer buy not so much, but maybe the ECM really is starting to fail. We'll see if a scan later today will yield any new information or new codes...

What brand O2 sensors did you use? My experience with other cars has always been that cheap eBay type O2 Sensors are extremely variable in quality.

I got them from FCP Euro. But I actually still have the old ones, so I"m gonna reinstall them this weekend to see if I get the same errors or different ones. Just grabbin' at straws at this point....

Not specific to the R230, but you should probably have a look at this site: https://us.autologic.com/news/merced...3-engines-me97

I would say that it shows issues that are very close to what you are seeing and it points to a bad module.

Yeah, I looked at the chart on that page and though it's not exactly the same model, I am getting the same errors. even after a key cycle. So now the search or a replacement ECM begins. :wall:

after you did this, you had to reset al adaptations, relearn ect with Xentry/Das
but I am still thinking this is or the engine module or your wiring

Have you done a detailed close inspection of the connectors at the cam position sensors and cam magnet to look for signs of oil? Same question for the O2 sensors connectors and ECU connectors. Have you sprayed the above mentioned connectors with contact cleaner?

I don't have a Xentry/Das setup, just a iCarsoft hand held scanner. But I'll clear all the codes and rescan, but basically, the same errors keep popping up. So I'm leaning toward a bad ECM as well.

Yes to all of the above. I replaced them all, cleaned all the mating surfaces and currently, there is on oil seepage anywhere near the sensors, magnets or connectors. ECU connectors are clean, but haven't checked the 02 sensor connections since I replaced them last summer. Will check that this afternoon though.

THANKS!

Are you saying oil is inside the harness?

No. I'm saying that I've replaced all the harnesses as well as the magnets and sensors. And post installation, there is no evidence of any oil on the harnesses or around any of the seals on the face of the cam shafts. I cleaned the area really well during the parts replacements to better detect any new leakages.

Solved ?
 

Would you tell me how did you solve the problem? I am facing the same issue