I just installed a Spectre CIA a little while ago and want to do better exhaust. Every place I call around here tells me either its illegal to replace the Catalytic converter or there is absolutely no improvement with a high flow cat and they are exactly the same cat as OEM. High flow is a sales gimmick they say.

So, since the 6 places I have called refuse to assist me with the Cat, my question remains, is it worth replacing my muffler? Any suggestions? Thanks.

 

The CATs installed on our trucks are already a high flowing CAT. Unless it's clogged, don't worry about it. Your muffler is a bit restrictive and as long as you don't mind a louder exhaust, I highly recommend Magnaflow mufflers.

You'll get MUCH better exhaust results if you also replace the factory exhaust manifolds with shorty headers that bolt to the factory Y pipe. When I did this to my Durango I did it in stages and I noticed a HUGE difference between just the muffler first, and then the headers. The sound was fantastic and the Butt-O-Meter felt a big change.

Also, by deleting the CAT you're inviting computer code issues.

 

You can put any muffler you want on there, and it will have little or no effect on performance.

As for high flow cats, on your truck, the restriction isn't quite as bad as on the older ones...... the point where the two pipes come together in front of the cat is probably the biggest choke point.

Depending on where you live.... emissions laws vary significantly from state to state, and even from county to county within the same state..... it may or may not be illegal to put an aftermarket cat on your truck.

 

ok. Is this a shop only work ordeal or can I do this myself? What parts do I need exactly for the exhaust manifolds replacements? Are these also called headers?

 

What state do you live in?

A fair few of the shortie headers have CARB numbers... (if you live in California, if not, not an issue.) And yes, they are indeed called headers. Most of the shorties are direct replacements, and come with all the hardware you need. Getting locking header bolts instead of using the ones that come with it is a better plan though.

 

I livenon florida. We dont have to pass emissions here. What are locking header bolts? Sorry. Noob here.

 

Also, i have been reading abot long tube and short tube headers. Whats the difference and does it matter?

 

Long tube is better for low end torque.
Shorties are easier to install and have better top end and mid range.

 

Shorties are basically direct replacements. They flow a bit better than the stock manifolds, but, aren't as efficient as the long tubes.

Long tubes are exactly that. The header tubes are significantly longer. (makes for better exhaust scavenging.) Of course, long tubes require extensive exhaust modification to make 'em work, and then you have to address cats.... To have a shop do it, you WILL have to install a cat, or two... (if you go dual exhaust.) Pacesetter makes long tubes for our trucks, and they also have a custom Y-pipe available, to make home installation easier. (but, no provision for a cat......)

Standard header bolts just screw in, torque 'em down, and you are done. The locking fellers have tabs that install over the bolt head, held in place in various ways (generally something like an e-clip) to prevent the bolts from backing out. (a common problem with header bolts.)

If I am reading this right, (big "if" there....) So long as you re-install a cat of some description on there, you will be legal. So, one of the universal cats should keep John Law happy.

 

Low end torque you mean better acceleration from stop or towing torque or is there a difference?