These cylinder's are all on the driver's bank of the engine. The problem is probably a failed catalytic converter on that side. Need to have the pressure on that side tested but I would believe the catalytic on that side has failed. http://images.search.yahoo.com/images/view;_ylt=A0PDoYBJUP1QVx4AYBGJzbkF;_ylu=X3oDMTBlMTQ4cGxyBHNlYwNzcgRzbGsDaW1n?back=http%3A%2F%2Fimages.search.yahoo.com%2Fsearch%2Fimages%3Fp%3D2002%2Bmercedes-benz%2Bml320%2Bcatalytic%2Bconverter%2Bexhaust%2Bsystem%26n%3D30%26ei%3Dutf-8%26fr%3Dyfp-t-701%26tab%3Dorganic%26ri%3D2&w=640&h=480&imgurl=www.lgauto.ca%2FMercedes%2FDSC06752.JPG&rurl=http%3A%2F%2Fwww.lgauto.ca%2Fcatalyticconverters.html&size=85.3+KB&name=Auto+Exhaust+Experts+-+Catalytic+Converters&p=2002+mercedes-benz+ml320+catalytic+converter+exhaust+system&oid=aef5e0b381eedee2be4297731779b899&fr2=&fr=yfp-t-701&tt=Auto%2BExhaust%2BExperts%2B-%2BCatalytic%2BConverters&b=0&ni=112&no=2&ts=&tab=organic&sigr=11d9rkpqc&sigb=14mhtbfc4&sigi=113qjvcq3&.crumb=XSu6yDnkqfu
There are four catalytic converters, two for each cylinder bank, the front ones are located a few inches behind the exhaust manifold flanges, and a few feet behind them are the other two. The biggest and most common problem with these catalytic converters is that the ones closest to the exhaust manifolds start to have the material inside them disintegrate into a dust that plugs the catalytic converters that are behind them. So, as the bad ones up front begin to come apart inside, they plug up and ruin the good ones behind them. When this happens anything over 2000 RPM creates massive back pressure on what ever cylinder bank its on and miss fires all the cylinders on the bank and instantly puts the thing it into limp home mode. It basically come down to replacing most everything from the exhaust flanges to the muffler.