No guts?

[RanchStroke]

Should I have trouble towing 8k pounds, to the point where I could not get over 55 on flat land? Programmer turned off with intake and 4'' exhaust. It is an 00 F250 excab.

[wingnuts514]

sounds like your tranny is taking a dump

[Dietoremain]

auto tranny??
do you have gauges??
should have no problem pullin that.

[bigcountrysg]

If you have gauges you can see what your trans temp is. But what I would do is unhook the trailer. Then go for a drive with the truck set up the same way. If you still have the problem then you have a drivetrain problem.

Is the engine running rough? I have to ask because it is possible to be an engine problem.

[sinnful_46534]

Sounds like something is wrong somewhere. Truck should have no issue with that weight.

[Dietoremain]

I can tug 8k of hay like its a toy, stopping well thats different lol.

check your fuel and air filter a well?

[RanchStroke]

I do have gauges and it was staying between 160 and 165. I had to take it to stock because my tranny was slipping to bad. Could a bad tranny cause it not to be able to build boost? I have a leaky uppipe also. It sounded like the stock wastegate was not able to hold, I could hear what I thought was it relieving continuesly whenever I hit the o/d button. Thanks

[Dietoremain]

if your tranny is slipping sure it could cause the power transfer not to be able to work and thereforeee...sounds like its trans time.

[RanchStroke]

It works just fine without the programmer?

[wingnuts514]

yeah it needs a load, just like trying to build boost sitting in park...no worky. oh and disconnect your waste gate, it might be bad too.