98 ML320 left me stranded
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Junior Member
Joined: Apr 2016
Posts: 34
Likes: 1
2011 E350 4Matic wagon
98 ML320 left me stranded
Cruise control engaged heading uphill, downshifted twice, then flashing check engine light, drastically lowered speed and RPM's and rough idle. Pushing down on the throttle has limited results after 2,000 RPM's and my max speed is about 5 mph with occasional bursts to about 20 mph while on a downgrade. Motor starts right up, high idle for a few seconds, then settles into a rough idle. My simple code scanner gives me nothing beyond cylinder 5 misfire, cylinder 6 misfire, and generic misfire. I tried to reset the throttle sensor by turning the key on for 3 minutes, removing it, and starting the vehicle to no result. I'm 70 miles away from anyone with a higher-end diagnostic scanner and can't bring it to a dealer. Any ideas?
Member
Joined: Aug 2018
Posts: 132
Likes: 6
From: Lawrence, KS
2003 MB C240. 2004 ML500, 2005 F150
those are the right bank, cylinders 4-5 and 6. P0300 is just saying there are misfires, the others specify which cylinder. Check wiring harness to see if its damaged. All 3 cylinders along the same bank seem very odd.
MBWorld Fanatic!
Joined: Oct 2011
Posts: 7,107
Likes: 765
From: Bronx, N.Y.
2002 ML 320 & 2006 ML500
Flashing CEL means that the misfires on that bank will damage the catalytic converter or the CAT is already damaged.
What you have to do is purchase Exhaust Back Pressure Gauge, remove the front O2 sensor on the left side, and install the gauge in the O2 sensor port.
Start the engine and look at the gauge. Any reading over ZERO means that your CAT must be replaced.
What you have to do is purchase Exhaust Back Pressure Gauge, remove the front O2 sensor on the left side, and install the gauge in the O2 sensor port.
Start the engine and look at the gauge. Any reading over ZERO means that your CAT must be replaced.
