Harbinder Ubhi

Hi guys, new to the forum as only had my 2008 plate C63 for about 2 weeks.
Started the car Weds morning and it had eml light on and was lumpy. Turned it off and re started it and it was all good again. Drove fine for last 3 days then again the same thing on a drive this morning, but EML light was on and off and car was a little jumpy. Parked up, went to the shop, got back in and its all normal again.

Plugged it into a mates code reader and it chucked up the following;

0745 The mixture (cylinder bank 1) is too lean. Current and stored
0749 The mixture (cylinder bank 2) is too lean. Current and stored
0629 Combustion misfiring has been detected. Stored
0645 Combustion misfiring of cylinder 2 has been detected. Stored

Have reset the codes and taken it out for a drive. No eml light but it has a very slight misfire. so slight you wouldn't notice it if you weren't looking for it.

Can someone please shed some light before I start spending money in my ever so short ownership!

Jasonoff

Searching the forums for your answer is my first bit of advice.

2nd, if you had searched, the common culprits for your scenario are a vacuum leak (air getting in after the MAF), or primary O2 sensors.

Harbinder Ubhi

Thanks for the reply. I should've probably added I'm new to forums as well as Mercedes vehicles.

As an update, took out the plugs yesterday which were all in a very poor state, looking through the service history it hadn't had a plug change for nearly 5 years.

changed the plugs, cleared the codes and ran the car. no misfire, drives like a dream and throttle is a lot more responsive.

However the codes are still there after being deleted but instead of being 'current' they are now showing 'stored'. Does this indicate that the fault is not there anymore but the code has not been erased properly?

Thanks again

Jasonoff

Misfire codes (since they could be serious) take time to clear from a pending/stored state.

A regular code reader can not clear them. You need one that can talk directly to the module.

Harbinder Ubhi

As an update;

I had someone come out and erase the codes, I think it was called Star Machine.

The fault is still there and the car is sometimes jerky and jumpy and sometimes it is clear and runs like a dream.

EML light is intermittent and the fault that comes up every time is bank 2. I've swapped 2 of the coilpacks over and it still says bank 2 which is confusing.

Has anyone had any experience? Can anyone shed any light on a suitable course of action to take...even if only a trial and error route.

Thanks