Headers + Exhaust explanation
 

Hey y'all,
I've been looking into headers to get my c5 sound just the way I want it to. One of the previous owners installed this magnaflow exhaust. I would like to add on to their work and install a set of long tube headers. Here are some pictures I took today while I had my car in the air.

Picture A:
https://cimg4.ibsrv.net/gimg/www.cor...5d72b13a46.jpg
X Portion

Picture B:
https://cimg2.ibsrv.net/gimg/www.cor...e16ce8a591.jpg
Where they link with the original exhaust system

Picture C:
https://cimg5.ibsrv.net/gimg/www.cor...875b0f93f8.jpg
Where they link with the original exhaust system, zoomed out

Picture D:
https://cimg7.ibsrv.net/gimg/www.cor...75deead7e1.jpg
The portion past the previous picture (The original exhaust system.

The point of my post here is to clarify
- What the things in picture D? Are they the cats?
- Up to where a set of long tube headers would go to? I assume they would be before what I think the cats are, but I'm not sure?
- What size of headers should I be looking for? I understand brands like Kooks have 1-3/4", 1-7/8", and 2' headers, but I have no clue what that means.
- What brands should I be looking for? I'm sure like any car mods they can get really expensive fast, so whats a good middle-ground "Value" set of headers?

I really don't know much about how exhaust systems work yet and would like to use this thread as a start.

I appreciate any and all responses!

Correct, picture D is showing your catalytic converters. To the left in that picture are your downstream O2 sensors which monitor the efficiency of the cats. This section of exhaust is known as the mid pipe. The magnaflow part you have replaced the original h-pipe section at the rear of the mid pipe.

Long tube headers will not connect to your original mid pipe with the cats. The collector of long tube headers come out too far to make it work. That's why most headers come as a kit with the mid pipe section. You can get kits with or without aftermarket high flow cats. Either way, the aftermarket cat will not be nearly as efficient as OEM, so they will prompt a check engine light.

You ideally need to get the car tuned after headers to get the most of the install. During the tune, the tuner can turn off the downstream O2 so you don't get the CEL. They are codes p0420 and p0430. I would always get the kit with the cats anyway as they still cut down on the exhaust/ unburnt fuel smell.

The 1-3/4, 1-7/8, or 2 inch dimension is the diameter of the header primaries. Lower diameter is more appropriate for mild builds, and leaves a little extra clearance. Larger diameter is for more wild builds.

On the budget side, speed engineer is the best value but there is a bit more work to do to get a quality installation because the mid pipe comes in small sections that get joined to the original mid pipe and it's all slip fit. If you search YouTube or this forum, there are plenty of videos and tips. On the high end side you have ARH and Kooks. Complete mid pipe section with those but they are pricey.

Speed Engineering about $600 1 7/8”

Kooks about $2500. 1 7/8”

People that have Kooks love them. People that have SE are very happy with them, and feel the extra assembly is worthwhile.

Also, add shipping and tax.

Good recap by dom04abp.

Mr Black has a good YT video on how to install.

You'll need two people for installation. Earlier cars (97-00) you will need to locate a later (01-04) dip stick/oil level indicator or modify the one you have. I went with Speed Engineering headers, X pipe kit and the steel gaskets on my 98. They fit fine. Plan on some kind of protection on the plug wires as they run right past the header tubes.

Narcotic Cow

You could drive up to Annah, Texas, just North of Dallas off Hwy 75, and have them install a set of 1 and 3/4" LG Motorsport Pro Longtube headers!!

They are at the upper end on price but I can guarantee you will be satisfied. That's what I did a number of years ago. Absolutely no regrets.

Good luck with your decision and Merry Christmas!!
VS