OM 948.961: Preparing for the East

Hello,

I've been assigned a task that I'm having some difficulties with.

I need to prepare an E320 CDI for a trip to the East.

It's a 3220cc engine with 204 horsepower, Euro 4 compliant, and equipped with a factory-installed DPF. The car currently has 130,000 km on the odometer. The car will no longer be able to operate within the EU, and will therefore only receive low-quality diesel fuel. Therefore, at the customer's request, the DPF must be removed, at a minimum. The goal is to make the car as reliable as possible for operation in that location. The customer doesn't fully trust the people there, so he asked me to take care of it.

As far as I understand, there's a pressure sensor and an O2 sensor located between the catalytic converter and the DPF, and it measures the differential pressure before and after the DPF. This way, the engine knows about the condition of the DPF. The DPF and catalytic converter are integrated into a single unit.

Can I simply replace the catalytic converter (CAT) and diesel particulate filter (DPF) with a straight pipe of the same diameter as the rest of the exhaust system? Are there any other things I need to consider?

I'm not really happy about it, but I understand where he's coming from, even though we only have one environment.
I hope you can help me with this.

Removing the DPF itself is probably not the problem; rather, it's the software of the engine control unit (ECU). It's possible that the engine will then run in a limp mode, and annoying exhaust/engine fault warning lights will come on. The ECU would then need to be reprogrammed by a qualified programmer.

Replacing the DPF with a simple pipe will be difficult because it will constantly trigger error messages. If you do replace it, the DPF needs to be reprogrammed. I would also recommend installing a finer diesel filter, as is often done in engine conversions.

Okay, let's talk about the environment, but honestly, the whole DPF (Diesel Particulate Filter) thing is the biggest joke since diesel engines were invented... I don't even want to talk about it anymore. I don't know many people who still have working DPFs because they've all just had problems with them. All the vehicles have been reprogrammed, and since then, the DPFs have been working.

Hello,

So, regarding the error messages, I also have some concerns, although I'm quite confident about that.

The O2 sensor is located before the catalytic converter, so the removal of the DPF is irrelevant to it. The pressure sensor before the catalytic converter is also primarily a safety device; if it becomes blocked, it shouldn't cause any errors, especially if the back pressure in the exhaust system decreases.
The differential pressure sensor can only measure the pressure difference, specifically between the inlet and outlet of the DPF, so it shouldn't actually be a problem.

What worries me is that the WIS (Workshop Information System) states that the DPF/catalytic converter is responsible for performance optimization and noise reduction.

That worries me, because you buy a car like that precisely because you expect it to be quiet and have good performance.

Hello,

You can pretty much disregard the "noise reduction" factor. Even if you completely remove the exhaust pipe from the loader, you won't immediately suffer hearing damage, as the loader itself absorbs a significant amount of "exhaust noise."

I tested the engine with a calibrated differential pressure sensor and drove a few kilometers. No error messages appeared. However, it would be necessary to test what happens after a longer period of time.

You can disable the DPF regeneration in the software, which can save some fuel.

I have deleted the document about the exhaust system for copyright reasons. It only shows the DPF/catalytic converter, followed by two separate exhaust paths, each with its own muffler.

Best regards, Rainer.

Okay.
I will not re-hire you again .

That sounds quite optimistic.

Is it correct that the cross-section should not be changed so that I don't experience any loss of power in the mid-range RPM?

Is there anything else one needs to pay attention to when building the dummy?

I wanted to reattach the cables and connections to the dummy, just like in the original.

Or could I simply empty the DPF, perhaps leave the catalytic converter as is (which I think would be a good option), and reinstall it?

'Are these vehicles not also sold in other countries without a DPF?'

Perhaps there is some information available about it, or some technical specifications.

Certainly, there are other versions available, but he specifically bought this one.
Unfortunately, MB doesn't provide any conversion manuals...

Rainer K. wrote:

... I tested the engine with a calibrated differential pressure sensor and drove a few kilometers. No error messages appeared. However, it would be necessary to test what happens after a longer period of time. ...

At some point, we should receive an "implausible signal."
The system anticipates an increasing differential pressure at the DPF. If this does not occur, the EDC reports an error.

I think this needs to be disabled from a software perspective.

Thank you for the hint. I will then have it programmed .