Have an 04.5 3500 runs good until about 2krpms and then has no more throttle. Truck isn’t throwing codes.

 

Sounds like it may be an issue with the Accel Pedal Position Sensor (APPS). This is part of the pedal assembly. If in fact this is the issue, the entire pedal assembly would have to be replaced.

 

Is there a way I can test this?

 

tps could be in one of three locations on a 04.5, at peddle, right above cp3, or a thrid that I forget...........

 

Is it auto? It could be under the intake horn, or the batteries boxes, I suggest you get a Jimbo's throttle positioning sensor from Geno's garage.

​​​​​If you get it, it will only work for trucks with the sensor mounted under the intake horn, I think.

Make sure you set it as the instructions say, otherwise you'll end up with like 1/8 of pedal movement with no response. Commonly known as dead pedal.