Exhaust sounds funny

[sparks57]

I just recently put a 4" exhaust on, and it sounded really good. But, after I broke my afc line and over-advanced the timing (new afc line and timing back to normal now) my exhaust sounds funny.



It sounds irregular, it used to be really smooth but now it's kinda... goofy sounding. When I hit 15psi I get a really strong drone in the cab now and my ehxaust kinda cackles and then gets quieter again.



Again, this did not start when I first installed the exhaust.



It just sounds kinda mushy... not smooth and regular like before last weekend.



My truck is making good power, and runs fine...



I'm sorry that it's this is so vague but I don't really know how to describe it without you guys hearing it! Shoot some ideas and descriptions of problems my way and maybe we can figure it out!



Thanks!

 

[Greenleaf]

My exhaust has this strange popping sound. Does it when the engine is cold/warm. Don't hear it when it's good and hot. Did it when the timing was factory and still does it with the new injectors. I have advanced it twice and still no change. Did it with the 3. 5" and still with the 4". There is one heck of a drone at mid RPM range that just about give me a migraine. That started with the 4" side pipe. Only when the windows are up.



-S

 

[sparks57]

That is exactly what mine does...



I was just talking to Mark at PDR and I described it to him... he said it sounded like "turbo surge".