MJMJ

I just put B&B bullets on my 2015 and it's still not as aggressive sounding as I want it to be. My plan is to get an x-pipe and I'm not sure if I should go with or without cats.

I had the B&B bullets on my 2005 C6 and they seemed to be much louder!

Any thought or does anyone else have this setup?

C7&7

Headers aren't in the cards? Going without cats is going to make it louder for sure.

However if you're ever going to go with headers the header package will come with a new X and you'll be buying one twice.

Just food for thought. If you ever planned to do headers that's the way Yiure going to get the sound you want. Oh and more power

_razar_

Are there still states out there that don't do emissions testing? I wanna live there!

MJMJ

do you know about how much it would cost for a header install?

sycraft

TSP Headers- No Cats, sounds great.... You just have to "know" people

slesher

Save some cash, get headers and matching x.

Then prepare to smile and giggle frequently while driving. Highly recommend Alleve for the eventual muscle cramps in the facial area.

mkr1966

Yes, in Iowa but probably you don't want to live here.

NTMD8R

I have left the resonators and cats in, but removed the mufflers,
and replaced them with straight pipes.

Louder, but not too loud.

tyho

I put ARH 13/4 headers and a Halltech carbon CAI on my 2015 z51 M7. Had the Bullets installed several weeks ago. The sound is awesome, I don't detect any drone. I am thinking about going with a Borla x pipe, no cats. You really don't need the secondary cats, no codes thrown and they act like a resonator and tone the sound down. ... but that is a project for next summer.

robert miller

So you put headers & Halltech on your car & it didn't thrown any codes at all. Robert

ilivas

I think FL as well,

m3incorp

Many counties in CO

Theta

Pretty sure the OP is asking about a catted X-pipe... Nobody has responded on that front, so I'll chime in if by chance I'm correct in my assumption.

The factory X pipe with the secondary 200 cats is not an emissions-control(led) part. It is downstream of the rearmost O2 sensor, and was included on the design to both regulate volume and pass the newer EU pollution control standards.

You will have no issues passing an OBD2/CAN, sniffer, or visual inspection with the factory headers and cats in-place and unaltered, regardless of the type of X-pipe you choose to use. Catless X-pipes are obviously the most popular, as they will increase your sound levels. For all intents and purposes, the C7's emission system ends at the secondary O2 sensor. The EPA rules dictating the definition of 'tampering with pollution/emissions control devices' has no bearing on devices placed downstream of the final monitoring device, at least under current US law. Totally different story in the EU.

C7-Beast

Many states simply plug into the OBDII port and if no codes, they pass emissions. Most states do a visual inspection but even most dealers won't care or notice missing cats. There are exceptions. NJ and CA can be tough but NJ is still easier to get by than CA.

In PA, if you put less than 5k per year on your car, it is emissions exempt. At my second home in Wayne County, PA, no emissions is required at all.

owc6

Unfortunately, the Bullets just aren't as loud for the C7 as they were for the C6. They made the sound lower and more aggressive/less European sounding than the stock/NPP, but they just don't measure up to the Bullets on the C6.

I've had Bullets on four engines, and this is what I've found: This list is the order I've found them to be loudest to "quietest":

LS3
LS2
LS7
LT1

People still stop and look because they are louder than the average, but they just don't measure up to the the LS3.

tyho

No codes, no issues, everything is smooth and sounds great. Very happy with the end result.

C7-Beast

I hope I'm wrong but many people put headers on and get no CEL for a while but eventually get one as the rear O2 sensors don't get hot enough since they are moved further back. Most tuners just tune out the rear O2 sensors.

Higgs Boson

you just live in the wrong county.

tyho

The ARH mid length headers don't throw a code. I've had them on my car over 6 months and no codes, no tune either, just better sound and performance.

elegant

THANK YOU THETA! So many of us appreciate your providing factual and relevant answers to our questions. You are a wealth of accurate knowledge!!!

John