Towed the race car today and I noticed going up any decent hill (65mph or so) I had the thing on the mat... 04.5 HO .....and the weird thing was it would'nt downshift?....It would downshift at lower speeds. Any ideas?...I towed thru West Virginia last fall and the thing ripped up the hills. Oh...the trailer is around 6k and I don't use the tow haul..it keeps it at 3000rpm when I do..Thanks

 

Fuel filter,lift pump or maybe a dose of bad fuel.

 

Could be regen.

 

Have you checked for leaks on the Boost side. I have read the boots sometimes come off. I have an 06 and tow a #6500 boat and never had the foot to the floor unless passing up a hill.

 

Thanks folks...I will check for leaks. I probably should have mentioned this also....the last 5 or so tanks of fuel have been bio-diesel. I did change the fuel filter after the second tank..

 

Even if your truck is completely stock, I would strongly recommend getting some gauges. Boost gauge, pyro, low side fuel pressure, auto trans temp to start.

The gauges are excellent as diagnostic tools when issues arise.
Example: lift pump issues, turbo problems, fuel problems..

 

Thanks...what brand do you recommend and where is a good place to purchase?...If Summit sells anything good...I have a Pro Shop discount with them.