Got a 98.5 2500 with the 24v. Fass Fuel System, straight pipe, bullydog high flow air filter. Boost gauge is hooked into the intake manifold. I am getting to 20-22 psi and then it feels like it is defueling. Can hold the throttle at half or full thorttle once i hit this 20psi and will not gain any. Going up hills while towing it just quits at 20psi and i start losing speed. New fuel filters, cleaned air filter, checked intercooler connections(thinking one made be lose or cracked and blowing out boost), no CEL.

I am wondering if this what other guys are getting with a samilar setup and if there is anyway to stop the truck from limiting the boost to this. How does a boost fooler work, solve my problem?

 

20-22 psi is above the nominal boost output for a stock 98.5 24v. 18 is supposed to be the max. You're getting an overboost warning that opens the wastegate prematurely. BD sells a boost fooler for about $70 that will trick the ECM to keep the pressure on a bit longer. I'd be careful though, you do have basically a stock set up and running higher boost than what that holset turbo was designed for could shorten its life.

 

try the boost fooler, and stay under 35psi on the stock turbo and you should be fine