car is misfiring on cylinders 4-5-6 Codes 304- 305 -306. Live DATA looks good except IAT. It is saying the Intake Air Temp is 192. Is the sensor bad? Where do I find the IAT sensor? Have already replaced the following: spark plugs, crankshaft positioning sensor, MAF Sensor, coils 4-5-6,Transfer case motor (motor not working causing car to go into limp mode) and the battery. Car ran great for a week, then started misfiring at high RPMs (4000), now misfiring at low RPMs (2000). Car has no leaks and no unusual noises. Don't understand IAT reading of 192 and can this be the cause of the misfiring only on Bank 2 cylinders 4-5-6?
What makes this problem better or worse?
Problem worse when engine is hot
How long has your 1999 Mercedes-Benz ML320 had this problem?
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That is a very high reading. Even on a 100-degree day at idle, your IAT should be more like 120ish. Although I don't think that's a normal reading I don't think it would cause a bad misfire.
Have you checked for vacuum leaks and fuel pressure yet?
Alex
