Loss of power, Started with towing and now at highway speeds. Please help!

[IanL]

I did the research, I knew the risks. I took every precaution I could within reason.

Did Trans/Diff/Engine oil when we got to our new house.

 

[RichardH]

I'm sure you did. You sound reasonable. Have the fluid changes improved the situation?

 

[IanL]

Unfortunately not.

 

[IanL]

Bump, anyone else have any input?

Thanks for everyone that did! I'll update with the solution when I find it.

 

[Msport]

Did you add friction modifier to the differential oil?

 

[IanL]

I did not specifically, but grabbed a brand with the right codes. I can post what I put in there in a bit and update tonight. It did seem a bit confusing at the time.

 

[Transporter]

I had a similar problem loss of power up hills or pulling into traffic:

Mine turned out to be the Catalytic Converters. Anybody with a 2003 or new Expy should run a bottle of Cataclean at 150K and ever 50 to 75K after that. Keeping the Cats clean and free flowing is a whole lot cheaper then replacing all four on a 2003 Expy!