Ordering some headers? Wondering which options? Headers banging the floorboard (motor mounts)? Answers below....


Click me for Motor mount/Transmission mount FAQ/Install!


EGR - Exhaust Gas Recirculation - Emissions controll device. Injects exhaust gas back into manifold for re-circulation. Came on 98-00 f-bodies only. Never on y-body or 01-02 f-body due to revised camshafts.

Removal Pro's:
Cleans engine bay, less weight, easier to work on things, pure air > burnt air.
Removal Con's:
Could cause you to fail "visual" inspection depending on how strict your state is. Removing without tuning work will cause Service Engine Soon (SES) light, dead giveaway to inspectors. Sniffer tests could be a problem as EGR cuts down on NOX gasses. Blockoff plates for exhaust manifolds required unless using "race" headers.

Example)
- Texas "visual" - pop the hood, don't look at anything, close hood, $12.50.
- California "visual" - pop hood, tech LOOKS FOR EGR, kicks you in the nuts.




AIR - Air Injection Recirculation - Emissions controll device. Injects fresh air into the exhaust gas before the cats. Helps them heat up to reach "emissions light off" faster.

Removal Pro's:
Weight, clean bay, no more annoying sound on startup, spare rubber hose to use on other stuff.
Removal Con's:
Only worry about VERY strict visuals (read: California) causing failure. Sniffer test can only tell before car is warmed up. After car reaches operating temp, the AIR pump shuts off and becomes useless. SES light will come on if system is removed unless codes are tuned out. Blockoff plates for exhaust manifolds required unless using "race" headers.



Rear O2 sensors - Emissions controll "tattler". Reads the exhaust gas after the cats, compares content to that of the front O2 sensors, makes sure cats are doing their job.


Removing the rear O2's is a must when doing headers. Even if cats and rest of equipment is used, SES light will still come on most of the time due to abnormal readings.

Solutions:
Buy O2 simulators - these plug into the harness and simulate a functioning cat. These have been known to STILL not prevent the SES light after exhaust work.
Have Rear O2's tuned out - better option, usually cheaper than buying O2 sims, guaranteed to stop SES light.

Best Option - Have REAR O2's, EGR, and AIR codes tuned out at same times, even if you wish to keep EGR/AIR. Any speedshop with LS1edit/HPtuners can do this. A friend who has a multiple car copy can as well. 2K2WS6TA has noted that the new Predator can supossedly delete the codes (per their website), but I'm not sure. Most handheld programmers can "read" the code, then "clear it", but this is not "deleting". When a code is "cleared", the SES light only goes away, but comes back when the car is turned off and re-started. If anyone has any info on this, post up!

Cost:
You can call around to a local shop and ask. I paid $75 at MTI, and should expect it to cost around that much. Some shops might even do it for free hoping to strike up some business. Go to LS1tech.com, click the top right button, and search sponsers by zip code and distance. You can also do a mail order if you don't have access to it. You just ship them your PCM, they edit it, and ship it back.



Links:

General - http://www.ls1camaro.net/sections.ph...ticle&artid=70
Very Nice Writeup - https://ls1tech.com/forums/generation-iii-external-engine/328977-exhaust-backfires-running-rich-poor-mileage-come-air-removal.html
Pics - https://ls1tech.com/forums/generation-iii-external-engine/480964-air-egr-removal.html
Lid Plug - https://ls1tech.com/forums/generation-iii-external-engine/483935-what-size-plug-side-air-lid-after-air-removal.html

Air Removal! With Pics! - https://ls1tech.com/forums/generation-iii-external-engine/673299-air-removal-pics.html

EGR Plug for manifold - 1-3/8" adjustable freeze plug from an autoparts store. Here's a picture of one......... http://www.franklinwaterers.com/images/zoom/explug.jpg




Having problems with front O2's? (insufficient switching etc.) This is a pretty good read.......
https://ls1tech.com/forums/generation-iii-external-engine/514521-o2-sensors-lt-s-not-hot-enough-tips.html









Adding links and stuff later, this was a quickie. Feel free to edit my post (mods), or add posts if you have helpful information.

 

Front O2 sensors
These are required items unlike the rears
You have 2 choices in what to use
1) Stock O2s- you can reuse the original o2s if you wish, be aware that you will have to extend the wire harness in order to reach the connector

2) Other o2 sensor- (bosch 13111vette rear o2s) These have a stronger heating element, and a longer wire harness, they can often solve front o2 insufficient switching errors, due to the higher wattage heater, also they eliminate the need for extensions, as the harness is long enough to reach the stock f body o2 connector


Extensions
If you use the stock o2 sensors (either new or your originals) you will have to extend your wire harness, you can accomplish this in 2 ways

1) Cutting and splicing the original wires- Pacesetter headers come with the wire and butt splices to do this, simply cut the wire (I advise doing one at a time to avoid confusion) and insert the supplied wire using the butt splices to join the ends, do not forget the heat shield tubing. You could also try to use 16-18 gage wire, that seems to match the stock wire size, from a local parts house if your headers don't come with any.

2) Purchase premade extensions- these are available, from many of the sponsors, in various lengths, 12", 18", and 24", they simply plug in between the f body o2, and the PCM harness, and extend the length so the o2 can be screwed into the header collector
There is a 3rd way to do it, and that is just buy the Corvette rear 02 sensor, the harness is sufficient length to reach the connector without the need for extensions or splicing

If you wish to use the original o2 sensors, you can have your tuner widen the parameters that trigger the SES light, so it won't set a fault code for insufficient switching (this can be done while eliminating the AIR and EGR fault codes)


That's my contribution, mods feel free to edit or add to

 

Thinking about running rear O2's with LT's and aftermarket cats? You'll probably still get coded and need to follow the rear O2 solutions in post #1.

 

Im looking at getting a set of Jet Hot LT without AIR/EGR Tubes, what else do I need to get for installation? Do I need to get the codes deleted right after installation or before. Thanx

 

You can get the codes deleted before or after. If you wait and do it after, you'll have the SES light staring you in the face for a little while.

You should not need anything 'cept for some new gaskets if your stockers are in bad shape. They are cheap so I'd go with a new set, but to each his own. Tons of people just re-use their old ones with no problem if it makes you feel any better.

 

will not having air shorten the life of ur cats?
also is the air pump fuse is pulled will that hurt anything?

 

There seems to be some debate on this. I don't believe it's going to hurt the life of your cats considering it only comes on for a few seconds after startup. I believe any unburnt hydrocarbons will be burnt off soon after it warms up even if it has no AIR pump boosting the process.

 

if i want to leave the air pump on the car, but not use it, can i just pull the fuse?

right now i have air shooting out the tube that used to go to the manifold. so i pulled the fuse and it seems to be ok. also now that i did that i dont have air going into the air box from the pump, is that really needed?

 

You can pull the fuse to disable it with no ill-effects yes.

That hose that runs from the air lid to the AIR pump is the air intake for the AIR pump, it never should have been blowing into the lid.

 

oh ok i get it now, didnt know it was pullin air from the intake. thanks!

 

Oh snap. My lid doesn't have a fitting for a hose to go to the air pump.

I removed mine and I couldn't figure out which hose it was talking about.

Maybe thats why my air pump was so loud.

 

MY question is which style of o2 exts. to use. Medically i cant crawl up under my car until august and my headers cant wait that long to go in. I cant look whether its flat or square, i have a 2000 z28 and i plan to delete AIR and EGR and remove the cats.

 

They are square with 4 wires. Most of our sponsors carry them and most people go with 2 24" extensions so they can be routed very well. If there's any slack, you can just roll a loop into them or ziptie them out of the way.

If you can't crawl under your car, I sure hope you don't plan on installing your headers! I would just wait untill you're able to do it yourself (I know it's a nail biter). You'll feel better about doing it yourself.

 

I know this is probably a dumb question but where do my front o2's go. if i have to reuse them where do they screw into? i bought a set of edelbrock victor series "race" headers and am going to get their competition y...

 

Theres should be a hole on the headers to screw them into.

 

I live in California and i have to pass my emmisions test... What would you reconmend?

I was lookin at a Set of Pacesetter LTs w/emissions, reading this the rear O2 become useless If i have that code "tuned out" or removed is that goin to effect my testing, or would i be better off gettin the simulator?

I suppose its good that i read all this before i made any purchases, even if it means i cant get me a set of LTs

 

I second that...I'm putting in Bassani cats on my '00 (as well as the y-pipe), and I'm wondering what else I can do here (considering I'm at Camp Pendleton).

 

So where exactally do the rear o2 sims go? I have to put mine in today so I can go pass inspection but I really have no clue where I should be looking to put them in at ( my boyfriend thinks thats its going to be really funny and a nice lesson for me to crawl under the car and do it myself). I have a 99 trans am. If anyone has any pics that would be great too. thanks

 

The rear O2's simply say to the computer "Cats are working, don't set the SES light". In california, they are going to hook up the sniffer and check you, so you might still fail even if there is no light on. If you put in aftermarket cats, it might not prevent the SES light from coming even if the rear O2's are plugged in (might not read in the same range as the stock cats and set the code). For this reason, you ALWAYS need to buy O2 sims or have the codes tuned out.

If you run LT headers, you're not going to be legal in any state with emissions, much less california. A friendly station is about the only thing that's going pass you. I wouldn't have a problem swapping out my whole system once a year or once every two years, but I'm alot more comfortable wrenching than most people are. If I was in cali, I'd go ***** out and just swap back to stock for emissions.


It is going to vary from state to state, I can't say what's best for you. Your best bet is going to be to check with your local boards or the regional section. Are you running LT headers?

When you crawl under the car, they should be close to the tailshaft on the tranny, or maby a little closer to the front on the driver side. The front O2 harness should already be plugged in, so this means you've only got 2 possible plugs under there that will plug into the simulators.

If your rear O2 sensors are screwed in and plugged in, you will have to unplug them from the harness, and plug the sims in their place.

What are your mods? Headers? ORY?

 

Just an offroad y pipe; she got them done today, i made her get on the ground HEHEHHE ( this is obviosuly the bf lol )