C180 Kompressor (M271) Fault Codes P0313 P0172
Discussion
Hello,
I have a couple of fault codes showing on my (girlfriends) 2005 C180 Kompressor automatic with 80k miles. (pulled with Torque and an ELM327)
P0313 - Misfire with low fuel
https://www.obd-codes.com/p0313
P0172 - System Too Rich
https://www.obd-codes.com/p0172
I'm going forward with the assumption that the P0172 code is being triggered by incomplete combustion in the misfiring cylinder so the cause of this seems to just be the misfire itself.
The only issue that I can detect when driving is that during cold starts the revs drop really low when it's put in gear (almost feels like it's going to stall). It doesn't stall but it feels very weak and it quite jerky when manoeuvring. I've cleared the codes and they periodically re-appear so something is amiss.
I suspect this issue is linked with the codes logged above, seems to be related to the air/fuel mixture but since this happens when cold I'm not suspecting the O2 sensor as the car should be running in open loop fuelling for that period. So maybe fuel pump or air leak?
My investigation so far has been;
- Checked the famous breather pipe under the intake (looks like a brand new part was fitted at dealer)
- Replaced the last original coil pack (the other 3 were replaced by the dealer before I owned the car so are only 2 yrs old)
- Cleaned MAF sensor (no change at all)
Since the generic codes don't tell me which cylinder is misfiring I intend to pull the plugs and see if any look fouled as a way of narrowing down which cylinder has issues. The plugs have only been in the car for 2yrs so I expect them to be in good shape.
Does anyone have any input on things I should look at?
I'm used to fixing things on my BMWs. INPA diagnostic is easy to get hold of and makes troubleshooting a lot easier but the MB Star system is a load more expensive so I'm relying on generic OBDII codes for this one!
I have a couple of fault codes showing on my (girlfriends) 2005 C180 Kompressor automatic with 80k miles. (pulled with Torque and an ELM327)
P0313 - Misfire with low fuel
https://www.obd-codes.com/p0313
P0172 - System Too Rich
https://www.obd-codes.com/p0172
I'm going forward with the assumption that the P0172 code is being triggered by incomplete combustion in the misfiring cylinder so the cause of this seems to just be the misfire itself.
The only issue that I can detect when driving is that during cold starts the revs drop really low when it's put in gear (almost feels like it's going to stall). It doesn't stall but it feels very weak and it quite jerky when manoeuvring. I've cleared the codes and they periodically re-appear so something is amiss.
I suspect this issue is linked with the codes logged above, seems to be related to the air/fuel mixture but since this happens when cold I'm not suspecting the O2 sensor as the car should be running in open loop fuelling for that period. So maybe fuel pump or air leak?
My investigation so far has been;
- Checked the famous breather pipe under the intake (looks like a brand new part was fitted at dealer)
- Replaced the last original coil pack (the other 3 were replaced by the dealer before I owned the car so are only 2 yrs old)
- Cleaned MAF sensor (no change at all)
Since the generic codes don't tell me which cylinder is misfiring I intend to pull the plugs and see if any look fouled as a way of narrowing down which cylinder has issues. The plugs have only been in the car for 2yrs so I expect them to be in good shape.
Does anyone have any input on things I should look at?
I'm used to fixing things on my BMWs. INPA diagnostic is easy to get hold of and makes troubleshooting a lot easier but the MB Star system is a load more expensive so I'm relying on generic OBDII codes for this one!
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