I have a 2001 QC CTD; 2WD; bone stock, and just ordered the power puck from DiabloSports. I want to get a little more power for towing my TT, which weighs about 7000#. With this addition will I need to step up the exhaust to 4 inch or will the stock exhaust work. This is the only power addition I plan on making to the truck. If I need to step up to 4 inch exhaust, I still want it to be as quiet as the stock with no drone. I have been reading posts here and have read quite a few posts about the MBRP exhaust. Also I know Jeg's has a 4inch exhaust with a straight through muffler. I need suggestions on which is the quietest exhaust and whether I even need to get 4 inch exhaust.

 

You might want to look into getting more fresh air into the engine. Look at after market air filters or do the BHAF. the Big Honkin Air Filter might be the cheapest alternative. Just do a search on this site for it.
just my 2c.
scotte

 

I ran EZ & 275 injectors on stock exhaust minus the muffler and never had the EGTs over 1150.