tbss714

on my 2000 clk 430 cab so i took it to autozone and pull out the codes po150. po305. po306. po300. multiple cylender missfire what will cause that i changed maf
and i need to replace one of the 02 sensor but before this took it to mb dealer and one of the spark plug wires was bad so they replace it what could this be please help

paulv

Which spark plug wire did the dealer change? P0305 and P0306 are for cylinders 5 and 6 respectively, which are next to each other on the left side (driver's side) cylinder bank. The P0150 is for the O2 sensor (before the cat) for that same cylinder bank (Bank 2). It's possible that a bad O2 sensor is causing the fuel adaptation to peg either extremely lean or rich, and this could be causing the misfire.

The P0300 is for random misfires and can be set when there are specific cylinder misfires or when other cylinders are misfiring but not enough for their specific code to be set.

More info is needed to diagnose the problem. Misfires can be caused by ignition, fuel/air delivery, or mechanical problems, so the problem needs to be isolated to one of these areas.

Is the CEL flashing? If it is, you shouldn't be driving the car!! Unburned fuel from misfires will destroy the catalytic converter.

Recommend that you post your problem in the section for your model/year so you'll have more people viewing it that have experience with your car.

Regards,
paul...

vettdvr

I have seen a CPS cause this type of misfire. Random signal from the hall effect sensor can result in dropping a plug out of the firing order and therefore throw a misfire code.

paulv

That's a good point, but I'm still curious that #5 & #6 cylinders are next to each other in the same bank and possibly they share the same ign coil -- I'm not familiar with this engine so I'm speculating. Without any other data (i.e., freeze frame data from the scan tool), I have no idea where to look next -- would really like to see what the fuel adaptation is doing. I know that many OEMs use the crankshaft PS and the camshaft PS against each other when the PCM does rationality tests on these sensors, but I have no clue to what MB does.

I hope it's any easy fix for him!

Regards,
paul...

RichardM98

One coil per cylinder on 3.2l V6.