[Need Help] P2187 Error Code
I have this error code (P2187 The mixture (cylinder bank 1) is too lean at idle speed.) for close to a year now which displayed the Check Engine Light in my car (W204 - C200 Kompressor sedan). I recently went to a repair shop to fix this and they changed both of my Oxygen sensors (costed me around $300 USD) but the problem still remains. The mechanic also checked my hoses and said they were fine. I am now puzzled now on how to solve this problem.

Does anyone have any idea? A couple of symptoms that I am facing along with this issue below:-
Some times my engine would misfire on the first engine start. This happens intermittently. It is not related to the car battery because I have a new AGM battery.This rarely happens nowaday after changing my weak AGM battery so I'm striking this off.During early morning cold starts, there is a whistling noise from the front part of the car (near the air filter) for about 1 minute. Driving the car with the noise will be sluggish. So I usually wait for a minute for the noise to go away and the car will drive just fine.A mechanic told me this is normal for Kompressor engines so I'm striking this off.

Attaching pictures of the error below:-
Error code displayed using my OBD iCarsoft MB2 OBD.
Last edited by echoes; Apr 13, 2019 at 10:54 AM.
I have this error code (P2187 The mixture (cylinder bank 1) is too lean at idle speed.) for close to a year now which displayed the Check Engine Light in my car (W204 - C200 Kompressor sedan). I recently went to a repair shop to fix this and they changed both of my Oxygen sensors (costed me around $300 USD) but the problem still remains. The mechanic also checked my hoses and said they were fine. I am now puzzled now on how to solve this problem.

Does anyone have any idea? A couple of symptoms that I am facing along with this issue below:-
- Some times my engine would misfire on the first engine start. This happens intermittently. It is not related to the car battery because I have a new AGM battery.
- During early morning cold starts, there is a whistling noise from the front part of the car (near the air filter) for about 1 minute. Driving the car with the noise will be sluggish. So I usually wait for a minute for the noise to go away and the car will drive just fine.

Attaching pictures of the error below:-
Error code displayed using my OBD iCarsoft MB2 OBD.
I too would be interested to hear if any solution was found.
Happened to a friends car who said the engine light (P2187) only came on around quarter tank of fuel. No garage could diagnose the fault including use of MB's star diagnostic tool l. Smoke tests done and existing sensors cleaned, tested and/or replaced.
Last I recall, they said keeping the fuel tank above half keeps the engine management light away while keeping them sane. Strange or what. Searching on forums, the issue seems to be quite rare.
Look forward to hearing back.
Thanks
I too would be interested to hear if any solution was found.
Happened to a friends car who said the engine light (P2187) only came on around quarter tank of fuel. No garage could diagnose the fault including use of MB's star diagnostic tool l. Smoke tests done and existing sensors cleaned, tested and/or replaced.
Last I recall, they said keeping the fuel tank above half keeps the engine management light away while keeping them sane. Strange or what. Searching on forums, the issue seems to be quite rare.
Look forward to hearing back.
Thanks
- First, I changed the original O2 sensor at the front to a Bosch O2 sensor. Didn't fix it because the error code was still there.
- I went to a place with experienced mechanics who used to work with Mercedes Benz dealers. They diagnosed my car and pointed it to the ECU Control Unit. It would be a costly repair. However, they said I didn't need to change it yet since my car is working fine.
- Eventually the error code went off on its own which I find very weird lol. Once in a blue moon the error will come back for a few days and then disappear again. Note that I didn't fix anything else... I only swapped to a different engine oil brand from Petronas to Liqui Moly.
Last edited by echoes; Apr 13, 2019 at 10:51 AM.
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