Mechanics

MB 320 MISFIRE CODES P0304 THR

1999 Mercedes Benz E320

Engine Performance problem
1999 Mercedes Benz E320 6 cyl All Wheel Drive Automatic 60000 miles

I have an 1999 MB E320 4-matic, which has the Check engine light on! I have read the diagnostic with OBD 2 reader and it it showing P0304 thru 6 error codes. Which I'm sure you're aware is all of Bank 2. My intuition would lead me to believe it is something in common with all 3 cylinders. The Bank 2 Sensor 1 was reading 0 mV and has been replaced but has not changed the misfire condition. Plugs and wires were replace 9 months ago with also the crank location sensor. What else could cause an entire bank to misfire. Or am I barking up the wrong tree? Thanks
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RLCofMN
August 26, 2010.



Hello and thanks for donating

The most likely fault here would be the ME-SFI control module seeing as how the plugs and wires have already been replaced.

Bluelightnin6
Aug 31, 2010.
But why would a faluty ME-SFI only have misfires on one bank?

Tiny
RLCofMN
Sep 2, 2010.
The control module could still be signaling the other bank. Have you inspected the MAF sensor by any chance? A faulty MAF sensor will sometimes cause this issue as well. It could even be a fault with the fuel and not the spark. If MAF is found good than may need to check the fuel injectors on that bank.