my last aircare has been done and now i can cleanup my exhaust, it's an '07 5.9, no smog stuff at all, run a smarty jr, which should i remove the cat or the muffler, can't remove both and go straight, hum would be right in my rev area of 2000 rpm, anyone have a thought?

 

cat is most restrictive.

They are expensive too... can get good money recycling them as they contain platinum and other precious metals in them

 

that was my thinking also, but i thought i would ask, we're close might cya around, take care.

 

We do have a dyno day coming up in a couple months in Auburn, WA.

Should be quite a few cummins trucks there. It is an event I organized for the cumminsforum guys that will be happening at TMS in auburn.

There are 2 guys from BC already that confirmed they will be coming down to attend.

We did the same thing last year and one of the guys from BC (same guy is coming back this year) came down and ran his common rail dually and got top hp numbers for the day. he was runnin twin turbos and twin cp3s.

 

sounds good, let me know when. does cat removal make a big diff in the sound compared to stock?

 

I wouldn't know. my truck never came with a cat

I do know in my old 86 v8 gmc pickup I used to have years back, removing the cat made the biggest sound difference.

no experience with diesel cats though. my truck has been straight pipped since day 1, an cats never came on 2nd gen 24v's from the factory because they passed 50 state emissions without one. even cali emissions.