Hey guys, I am new to the scene. Recently bought a 2004 Excursion with the 6.0 psd and 85,000 miles on it. Heres the problem, I was towing about 4500 lbs on a flat level highway doing about 70mph in tow mode and I notice a droning noise coming from the exhaust. As I drove, I realized the turbo wasn't producing any boost. Truck still drove fine but I had to be careful how hard I pushed it because the EGT's would easily climb well past 1250 if I didn't let up on the skinny pedal.

Truck has the following upgrades:

Bulletproof diesel oil cooler
Bulletproof diesel EGR cooler
Garrett Powermax turbo
MBRP 4" turbo back exhaust
Metal intercooler tube

I am monitoring it with an Edge CTS unit with egt probe. At the time this happened I was running a SCT tune for towing +65hp. It was a tune on the X4 programmer that came with the truck. At the point this happened, I had already towed the boat almost 4 hours without any problems.

The Edge CTS read these 4 codes:

P0069 - Barometric Pressure Correlation
P0470 - Back Pressure sensor circuit malfunction
P0478 - Exhaust pressure control valve malfunction
P2262 - Turbocharger boost pressure not detected - mechanical

Where should I start? I checked under the hood and didn't see anything obvious, looses hosed, fluid any where, etc.

Thanks in advance for the help!

 

I see your in the right forum, check the tec folder. Your exhaust pressure tube can clog, The turbo unison ring gets stuck

 

Read the VGT and make sure its moving. If the vanes are stuck, I'd start there.