I am looking to get one of the Autel scanners for my 2004 6.0 Powerstroke and am wondering if they are capable of reading all of the codes that the truck and spit out. I am having a problem with my 4x4 engaging and have tried basically everything with no luck. I am also having trouble with my emissions out of the tailpipe and am hoping that an Autel scanner like yours can read more than just the OBDII codes that my basic scanner does. 

Does your scanner offer any of the "tuning" capability that claims to offer timing and boost information?

Be carefull when comparing those readings, they all should be about 14 PSI.

If the exhaust back pressure readings are off (or boost pressure) it can cause your issue. If OK, take the boost sensor hose off of the intake, remove the fitting in the intake for the boost pressure hose and make sure that the hose and fitting are open.

 It's common for the fitting and hose to plug up. let me know what happens.

Kevin