My ml320 OBD II engine code readings is showing misfire on all six cyllinders. I changed the plugs but still get the same readings. The car is actually running good but at times it will sputter and act like it does not want to accelerate but then will smooth out and run great. When it does not smooth out I just pull over and stop the engine and restart it which smooths it out and it runs fine again. Could this be some sensor malfunction that would cause this misfire effect on the engine???. All the engine codes show cylinder 1 misfire, cylinder 2 misfire etc. all the way to cylinder 6. Help me is you can and post your comments and experiences.

Thanks so much......

 

could be clogged exhaust cats
or bad air mass meter. even plug wires too.
did you erase codes after replacement of plugs and if so you need to rescan to make sure codes were erased

both are common problems

Jerry

 

sounds more like CATS blocked.....

 

Please replace your cps crankshaft position sensor with OEM Bosch and you will see the results. Maybe you are taking your engine into higher RPM at the time of accelerations and this sensor can't keep up with providing correct signal. Then ECM will stop firing couple of cylinders with detected misfire and you have to restart your car to get it back to normal (all 6 cylinders). But your check engine will reset later by itself. Check your sensor, because there is two different connectors used, depends on your year. This should cost you about $50, a lot less then cat convertor.
I've ben in your situation, new plugs, coils, wires even injectors, all brand new and OEM.
Check older posts on CPS replacement.
I maybe wrong but this is the first and the most inexpensive step that you should take.

Bernard

 

Thanks, this sounds like very good advise. I shall take it and look for the Bosch CPS and install asap.... I'll let you know the results... Thanks so much again for your help and words of experience... BWR ( bwrumfel@yahoo.com)

 

208k kms, having the same problem, misfires when cold runs great after the engine is hot. Also ESP, ABS, ETS, SRS warning lights comming up all in one day..any suggestions

 

Try changing your CPS to fix the misfiring and stop light switch (brake pedal switch) for the warning lights, then reset them by turning steering wheel lock to lock (max. right to max. left) some times you have to turn them twice and all the lights should go off. Switch is about $10 and the sensor about $50.
Good luck,
Bernard

 

Do you think same problem is when you get message "cylinder 6 misfire"?