After fixing a bad fuse box (fixed vac pump and A/C controls issue), I was towing the RZR from 2300' to 8000' but while on flat ground I got a CEL; P1247 (low boost). Cleared the code but it came back as I was slowly going uphill (slow being key). Friend who owned a 2000 7.3L X (wrecked) and now a 2005 6.0 X says his limited time driving my X it seems real sluggish. Fast forward back home and I plugged in Torque Pro and Forscan to check the data. Following the Oregon Fuel Injection, Inc diagnostic I started logging data. The EBP, MAP, ICP and IPR lines are expected values; Excursion is Torque Pro data for my truck (I have the Ford extended package).

First off, Forscan says the PCM believes it's pretty high, no where close to local conditions. Not sure if that's the start of the boost issue. Torque Pro also reports Baro 0.0 when I added the gauge, so could be a TP issue there. My X also starts with low EBP and MAP values but similar to the PCM. Boost readings seem weird (-3.6 to 5 psi). If I do a simple MAP - Forscan BARO the boost data looks better, but low. I changed the EBP sensor with Motorcraft (DPFE3) and EBP tube (from Riff Raff, came in Motorcraft packaging) several months back. I back probed the MAP and got a 5.01VDC for the reference. I can't remember the other 2 values but will recheck soon. Also, unable to move the waste gate rod. Not sure if this is data as I struggle to get my meaty hands in there so take it for what it's worth. But it could be stuck.

Question: Is this data indicative of a boost leak, MAP issue? Can a boost leak result in low KOEO numbers? Seems the PCM needs a BARO tune up. Thanks

 

After all that, lower CAC boost was loose. 20 years in diesel environment and the boot was weak and the clamp would not seal, only slip. New Riff Raff boots and clamps and I’m back up to 15psi when I floor it. Had the truck a year and it never performed like this. About time I got around to checking it out.