My exhaust is very quiet, it sounds almost identical to stock. I have the banks cat-back. I was thinking of deleting the cat to open it up some more. Banks told me I will get engine codes if the cat comes out. They also said there is no real benefit (2-5hp) to taking it out because they tested with and without.

How much of this is true?

I want to be able to hear the turbo whistle through the exhaust

Do a search on cat and exhaust threads. There are many threads that have been addressed thoroughly about this topic. IMO pull the cat and muffler off and block and finger it. Youll get the turbo sound you want.

Andy S

Like Andy says, You will definalty get some wistle by removing the Cat & Muffler. Put a Fingerstick in there and that will clear the codes.

I was just wanting to see if anyone had tried it or was running an open exhaust with 6-gun and no finger or blocker. If the fingerstick blocks the codes then what is the purpose of the egr blocker? I understand the function of an egr but I was wondering what gain (if any) was achieved from blocking it?

Along these same lines, can't you do the samething with EFI live? ie no need for either the blocker or the finger stick?

The blocker plate is not to clear the codes (this is the fingerstick)but only to prevent the gases and soot from recirculating back into the intake. I know of a couple of guys who dont have finger or plate and dont throw any codes but it is just a peace of mind thing for some. It is a reccommendation to block it to have "cleaner" air entering. Along the lines of EFI live, yes you dont have to put in a fingerstick becasue the egr can be turned off which eliminates the code but the blocker is still reccommended. Hope this helps

Andy S

I pulled the cat on mine and put in a blocker plate, only set egr code intermittently, but did install a finger stick to stop it. My setup rocks pretty well, made 464/793 on dyno.

I have the six gun pda volant air silverline exhaults and have thrown no codes in the area that you are refuring too! 2wd reg cab lb and no kitty