'01 c320 misfire issue
 

My Lady friend has a 2001 MB C320

cat was rattling and was having misfiring problems, replaced the DS cat, missed still on the way home from the shop, but then it stopped for a long time, now it started again

cold starts W/ hard acceleration

hard acceleration

bad idle synonymous with a misfire problem

check engine light flashes obviously

my VW scan tool gets generic misfire codes, problem is intermittent

any ideas from you guys I am completely unfamiliar with these MB's and need some help, thanks in advance

TRON aka VWguy

Possibilities are plug misfire causing ecu to shut off that injector.

Also try a wriggle test of loom in engine bay.

Watch for acv ripple on the Alt Batt+ terminal. Over 0,07acv seems to be the max on most I have checked.

Poorly mixed Ethanol in the gasoline or too much Ethanol...usually not more than 10% is the norm but we had one pump here with 15% and was causing complaints.

Have you checked cylinder balance or smoothness...should see a % .

After market cat's are commonly notorious to not work correctly . If the cat' is working sub standard, the bank 1 and 2 #2 o2 sensor will report unacceptable reading to ecu which will lite the MIL.

Someone else is bound to post some more pointers.
Without a dedicated MB scanner your are at a serious disadvantage.


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Cat is M.B. cat from dealer

thanks for the tips haven't gotten a chance to try them out cause my GF and I have been real busy

any other ideas??

Like I know with VW's coil pack go out and with Audi's ignition switches or control modules go out, was curious if there are common problems with these buggers or am I kinda shooting in the dark with these tips...

Hunt around with the 'Search' feature on here. Bound to be someone BTDT.

Until you can get a STFT/LTFT and Cylinder balance I would suggest you wait until you can.

V6 init ? IIRC the crank pulley on those wos a problem...they wobbled until they fell off, taking chunks of timing cover with it.:vbac47679


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Plug wires can go bad often on these and cause misfires or rough running. Without guessing in the dark it will be hard to tell which wire of the 12 is causing it, you really need to hook up a MB scanner and display the "smooth engine running" screen. it will tell you immediatly which cylinders are misfiring out of range and by how much.