I just did an exhaust job on my 99 SS. Pacesetter Longtubes w/o AIR or EGR provisions, ORY, and SLP Loudmouth 2 catback system. I did the header swap myself, then paid a shop to weld/clamp together the rest. I just wanted to give a quick writeup with some things i ran into and didnt find any answers to, as well as the key pointers that are littered and beat to death on these forums, but dont hate! Before I get started, I havent dont any real work to a car without the help of my dad, and am by no means all that technically experienced, however I am somewhat technically inclined.

If you are installing longtubes, which I did, you need either o2 extensions or the Bosch 13111 Rear Corvette o2 sensors which reach farther back and also work in a more acceptable heat range from what I understand. You are moving your front o2 sensors back farther and will not be as hot as the location in the manifolds that the stock o2 sensors are placed. Sometimes this throws a code with the stock o2 sensors, sometimes it does not. Safe way is the $110 for the pair of corvette o2 sensors, daring/thrifty way is $30 for o2 extensions. My o2 extensions should be here in a couple days, so I'll install em, drive around a bit, and update whether or not my computer is throwing me the codes.

If you are deleting catalytic converters, you will need o2 simulators OR a tune of some kind to delete the "inoperable catalytic converters" code. The rear o2 sensors have nothing to do with performance, they are only there to compare the oxygen content after the cats to the oxygen content before the cats to make sure the cats are doing their job. You cannot have any code appearing during inspection, or the inspector WILL sniff your tailpipe which will fail you permitting you deleted the cats. Cars with OBDII (96+) are NOT sniffed unless a code is being thrown (from what I understand, a SES light being triggered for any code initiates a sniff; no SES light means a sniff is not required. If the inspector performs a visual inspection and does not see a catalytic converter, does this intitate a sniff? Someone confirm or correct this please).

Before I started on the exhaust, I deleted AIR and EGR. 1998-2000 F-bodies have EGR, 2001-2002 F-bodies and all Y-bodies do not. It is really self-explanitory, check the sticky on the ls1 external engine thread and theres a couple writeups with pictures of where the AIR pump and EGR system is; once you locate the components, disconnecting and uninstalling them takes about 20 minutes. If you do this you need that 1 3/8" freeze plug from an auto shop to plug the hole it will create in your intake manifold. Also try to get headers without AIR and EGR provisions, or you get to plug those holes which is no big deal anyways, more of an annoyance.

1) I got under my car, looked at some flange studs and nuts, and said to myself....no ******* way im gonna be backin those things out (due to rust; my car lived for the first 60,000 miles in Chicago). So I paid a shop $30 to heat up all bolts/nuts and be able to back em out for me. Basically $30 to prep the exhaust for me to disassemble easily.

2) The Catback will not come off of a car on stands without cutting, since it runs over the axle and will not come off with the springs compressed. It may be able to slide over the axle if the car is jacked up from the frame somewhere while the springs are extended, I haven't heard either way. I would have sawed it, but since i didnt have a lift to get easier access to it, i left it bolted on for the muffler shop to cut off for me when they put my ORY and Catback system on.

3) I had my car jacked up about 8" in the back, 2' in the front. It took 8-9 hours from stock exhaust on to open longtubes driving toward the muffler shop, but hopefully with a couple pointers it will be reduced to 4-5 for you guys.

4) The passenger side stock manifold is the worst. Namely, the #1 bolt if you label the bolts rear-to-front like so: [*O*O**O*O*] , where a * is a bolt and a O is an exhaust port. #2-#6 are accessed from the top of the car with the spark plug wires disconnected and off the car. #1 is only accessable from the bottom of the car. The bolts are 10mm, and I used a socket wrench with a combination of different lengthed extensions, and also a ratcheting wrench something like these (http://www.made-in-china.com/image/2...-JD28000-.jpg). I left the spark plugs themselves in cuz i didnt really think about it till the manifold was free and coming out; I had plenty of room to work around the spark plugs and not endanger them (to be honest, i completely forgot about em ). All manifold bolts on the driver's side are accessable from the top and used the socket wrench. The driver's side has an assload of room to work with compared to the passenger's side.

5) Putting the Pacesetter longtubes in was easy on the passenger's side; they slid right in. I had to drimmel away maybe 1/8" of a casting tab on the driver's side. The drimmeling took like 30mins, a sawzall or whatever is much quicker I hear.

6) Save those stock cats! Everyone and their mom on this forum buy em in a hurry!

Well thats it. If you live in the DFW or Denton area, Ill be happy to come over and help you out on a weekend with the whole job as long as you give me some beer Just shoot me a PM. It was hell of a job, but I look back and actually enjoyed it. Now that I know what I'm doing and will know what kind of tools I'll need around me, doing a header swap should really not take more than 4 hours including breaks.

 

Take your time, patience. Good luck

 

what parts did you weld together?

 

between the Y-pipe and I-pipe of the catback, i cant remember which other one exactly but they also put a "boot" i think they called it, a couple quarter-inch welds on the catback, between the 90* elbow and over-axle to prevent it from twisting.

 

Another tip:

Loosely zip tie the gasket to the flange (on each end - 2 ties) on the headers to eliminate one more thing you have to hold.

That way you can concentrate on holding up the header and aligning the bolts. With this method, I usually start the center bolt first to hold it up, then move outward. Once you have two or three in there, then cut off the zip ties and start the rest.

This worked great for me when I installed my Kooks by myself...

 

kipmansloka maybe you can help with my headers installation this week, I stay in Irving.

 

Aight, i have a weird class scedule during the week so if you wanna do it saturday or sunday, ill be glad to help. just PM me with the day and address, and ill probably be there.

 

we used some silicone to hold the gasket on

 

most of the subjects discussed are in the exhaust sticky