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?

Did you also get code P0300?

I believe it did. I can re-scan tomorrow morning.

Please post all of the codes that are stored,

I got codes p0300, p0304, p0305, and p0306 along with a flashing CEL

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.

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.