I recently removed my stock exhaust from where the cat bolts up to the down pipe. It was in bad shape and i had no time to go to a shop. I installed 4 foot of 3.5" pipe with a 90 and 18" of tail pipe. After doing this I noticed that it smokes pretty good upon start up. It never did this before. This morning when i got up it was 30 outside. I started the truck and it warmed up for 30 min before heading to work. All the way to work when i was not accelerating I could hear what sounds like air being purged throught the exhaust. As soon as I accelerate it goes away. When I first changed the exhaust I would here this same sound shortly after start up bu it was for just a couple seconds. Does any one have any input on what may be going on.. Thanks!!

 

Sounds like your EBPV (Exhaust Back Pressure Valve) is closing. It will close when the temp (outside air) is cold and restrict the exhaust flow to help the engine warm up faster. Once the engine is warm, it will open up. If you do not want it to close, just unplug it. The connector is on the left hand (drivers) side near the bottom of the turbo.

 

yup, ebpv.... take it off and gut it but for now at least remove the actuator rod

-cutts-

 

What is the benefit of "gutting" this valve?

 

Gutting the EBPV insures that it will not close on you. It also removes the obstruction in the exhaust and allows for better flow.