Lukec_1994

Hello, I am new to this so hopefully I can find some answers as part from what I've been doing. I own an 02 Mercedes Benz c320 and the car was great till the alternator went and I needed to change it. Ever since then I've been having issues with misfires in cylinders 4,5 and 6. I took the car to my local Mercedes Benz dealership and they said to change the coils, spark plugs and wires, even though they were changed not too long ago, and that should fix my issue. I asked what if it doesn't and they said we need to start somewhere. So I replaced those, still had the same issue. Car runs and idles rough when you really get on the gas. I took it back and found that the Mass Air Flow sensor needed to be replaced because it was bad, I changed that and reset the ECU and it still gives me the same issue. I checked all fuses I've replaced everything I have been told to and haven't found the solution. They mention the cats going bad but those were taken out and had a new exhaust system etc put in so I know its not that. I have no idea where to go from here, someone please help! Thanks.

LILBENZ230

So you have a CEL with misfires on cylinders 4-5-6? Or just sluggish acceleration?

Lukec_1994

Getting misfires for 4 5 and 6

samaritrey

Just to be clear the car has all new ignition wires, plugs and coils?
What brand of parts did you use were they OEM/OES?
Have you tried to unplug the MAF and see how it is?

Lukec_1994

Correct and new maf

Xtrmsnds

Im having the same issue guys

cylinder 4,5,6 misfire codes
real sluggish performance and ussually cant get over 45 mph
no cel code either

somebody know what this is

tomorrow im going to swap around the coils and see if it makes the other cylinders error out that way i know to replace those il let you know if i figure it out

Kurklander

I had those symptoms and the problem was the throttle position sensor. The shop mechanic knew that it was the TPS when I first talked to him on the phone. Fixed the problem with my 2001 CLK320.

Xtrmsnds

guys I know this sounds strange but i got same errors and it turned out the two catilytic converters were bad in the middle of course after i changed spark plugs and wires so the muffler shop cut them off and made straight pipe and left the other two on car is just as quite but alot more peppy