Hey guys, I'm working on a customer's E550 that is idling very high and running rough. It's idling at 1400 rpms and I have codes for the ICP (P1211, I just replaced that sensor) IAH (P0541) and have cylinder contribution codes for cylinders 3 and 6. I'm about out of ideas, I checked the UVCH. I also just replaced the glowplugs, it ran fine right after doing the glowplugs then started doing this. Thanks for any help!

 

Any smoke out of tail pipe or evidence of oil in tail pipe?


did you use OEM ICP or aftermarket? If you unplug ICP while running what does it do?

 

I ended up using an aftermarket sensor against my judgement because she gave me a $300 parts budget to fix any oil leaks, change glowplugs, and icp sensor... I ended up going over that by quite a bit obviously as it was so she didn't want to spend the extra on the motorcraft sensor. I'll have to have them check the oil in the tailpipe, I don't really have easy access to the truck because it's about 20 miles away from me and I'm doing it as an extra side job as a favor so I'm not able to get to it a whole lot between working full time and school.