Questions about mods and emissions testing

**wildhare** · 11-26-2009, 06:40 AM

I just purchased a '99 Z28 with LS1, bone stock at the moment, and I want to go bracket racing while keeping it legal and able to pass the state emissions tests. I hope to run in the 12's which from what I've read is easy to do with a few modifications like a LS6 intake and long tube headers with improved exhaust system, maybe some slicks and a few chassis improvements.

So I have the basic tools but I have a major question. I read here in the forums about people changing this and that, but there is never any mention of how the various changes affect emissions performance and testing.

So my question is, how do I know what I can do and what I can't. I see a lot of guys using an off-road Y, does this eliminate the cats and if so what happens?

I see the LS6 intake does not have an EGR, same question, how does this affect the emissions and the ECM. And what about camshafts? How far can I go without crashing the whole emissions deal?

I'm thinking that this information might be all together somewhere in a book, can anyone point me to a source for the info I need?

What I don't want to do is put a bunch of stuff in only to find out I can't get it licensed any more, it's too nice a car to make it a pure race car.

When I had it inspected the first time the guy just hooked up to the car's OBD-II, no tail pipe testing. What are they looking for in there and how far can I go?

I need knowledge. It seems nobody talks about this, is this because it's all automatic or is it because they don't care about it?

TF

**gnomee** · 11-26-2009, 07:24 AM

Most people do not cover this issue because they just don't care. Like here in Oklahoma we do not have any inspection at all.

An off-road Y is exactly that, for off road so it does not have cats.

You can make all the modifications you want up there without removing your emissions but it will cost you more.

You can get an LS6 intake with EGR from SLP.

You can get headers with Air pipes on them.

You can get performance cats also.

Camshafts I have no idea about, someone else will have to help you out there. Really that is going to depend on tune and what the tail pipe test is looking for I imagine.

**dklowrider** · 11-26-2009, 12:45 PM

egr and a.i.r. can both be tuned out of your computer, as well as the rear o2 sensors. i sent my pcm to Tuned by Frost. emission test went fine for me. i don't know how far you can go with other mods before you shouldn't use a mail order tune, but look him up and you will have all your questions answered.

**gnomee** · 11-27-2009, 09:34 AM

Originally Posted by dklowrider

egr and a.i.r. can both be tuned out of your computer, as well as the rear o2 sensors. i sent my pcm to Tuned by Frost. emission test went fine for me. i don't know how far you can go with other mods before you shouldn't use a mail order tune, but look him up and you will have all your questions answered.

Do they do a tail pipe test on your car? If you have no cats, a tune is not going to help you pass that...

Plus a tune is not going to help you pass a visual inspection of the engine with all egr and air stuff removed.

I guess it really depends on how inpections are done in your state. Even we had inpections here in OK I knew a shop that would "pass" me anytime.

**SOMbitch** · 11-29-2009, 02:45 PM

If inspectors are really on there game they will do a visual and bust you on AIR /EGR even though it can be tuned out so it will not throw a code. They will see it is not there.

Also any LT header is TECHNICALLY illegal according to federal law because it moves the cats back from their original location. But as long as you have Cats most shops will pas you....

If they sniff the tailpipe like in California a WELL tuned 224/224 on a 114 LSA can pass...

Basically you just need to talk to some guys and learn where to go.....

**wildhare** · 11-30-2009, 04:44 AM

Originally Posted by gnomee

Do they do a tail pipe test on your car? If you have no cats, a tune is not going to help you pass that...

Plus a tune is not going to help you pass a visual inspection of the engine with all egr and air stuff removed.

I guess it really depends on how inpections are done in your state. Even we had inpections here in OK I knew a shop that would "pass" me anytime.

It's not really clear to me exactly what they are doing. I used to live in California so I'm very wary about doing anything to the car.

In Texas in the major metropolitan areas they do a dyno/tailpipe test on some vehicles. But when I took my car in to get it inspected they just plugged the machine into the car's OBD-II connector and read out the details. I missed whether they did the dyno test, wasn't there the whole time.

What I'm thinking of doing is replacing the 320HP LS-1 with a newer LSX crate engine, and I'm looking for somebody who has the actual answers about what I must do to keep it 100% street legal including smog stuff.

Just getting it past the smog test is only one part of the problem, I want it to be clean and to have some resale value too. I know I can met it to pass if I find a shady shop, that's not the point. I want it to pass at a good shop that's going by the rules.

TF

**wildhare** · 11-30-2009, 05:20 AM

Originally Posted by SOMbitch

I

Basically you just need to talk to some guys and learn where to go.....

I thought that was what I'm doing here.

TF

**kool-aide** · 11-30-2009, 03:10 PM

I'm not an expert, but as far as I know you can't modify any of the emissions equipment on any of your emissions equipped cars.

My brother lives in Texas. He has JBA headers because of the emissions testing.

You will need to research your state laws. My opinion is keep everything on the car, working, and in the same place the factory put it. My JBA header example demonstrates a part that has a CARB number and does not modify any emissions equipment, not even the location.

I don't know about Texas, but in my state we have access to the state laws via the state web site. Maybe you can try searching for the Texas state laws on the web.

Even in my state, which has no testing, it is still illegal to mess with any of the emissions equipment.

Good luck. When in doubt find your State laws,

, oh and those federal laws too. I can't say for sure if my brother's truck is even legal. He has done a crap load of work to it, but I do know he didn't remove, move, tune out, or touch any of the emissions equipment.

**402 Guru** · 12-01-2009, 05:45 AM

my suggestions would be to do some research of your local shops for a reputable Tuner that knows your local state laws and that know what your local laws regulate and mandate so then u can mod your car sweat free , and These F-Bodys Make Awesome Bracket Cars the 1st Thing I would Suggest if you are Bracket racing get a electric water and also are oil pumps are knows for going out at past7000 rpm's a medling oil pumps are fine pices Good Luck and Happy Modding Sir

**SOMbitch** · 12-01-2009, 12:43 PM

Originally Posted by wildhare

I thought that was what I'm doing here.

TF

What I meant was talk to some modded guys at your track and find out what shop will let you slide. But you have already stated you don't want to do that......Better knock the headers off your mod list then

**wildhare** · 12-02-2009, 01:03 AM

Thanks for the effort. I found a lot of the information I needed.

The important piece is that in Texas (in the metropolitan areas) like almost every other state you are not allowed to change the emissions stuff until the vehicle is 24 years old, so technically I can't really make any changes at all.

This car is fast enough to bracket race as-is, I just want to go fast enough to not humiliate myself. So I'll restrict my improvements to chassis and tire changes to make it consistent which is the key to a good bracket racer.

If I feel the need for speed I'll get something old enough that I don't have these problems or I'll move to the boonies.

TF

**basballny2** · 12-02-2009, 01:29 AM

u can do whaterver you want and make it as illegal as you want as long as you know someone at a shop willing to pass you for a few extra bucks....

**Spaz** · 12-02-2009, 04:40 AM

Originally Posted by gnomee

Do they do a tail pipe test on your car? If you have no cats, a tune is not going to help you pass that...

Plus a tune is not going to help you pass a visual inspection of the engine with all egr and air stuff removed.

I guess it really depends on how inpections are done in your state. Even we had inpections here in OK I knew a shop that would "pass" me anytime.

most people don't even know to look for that...

**SOMbitch** · 12-02-2009, 05:21 AM

Originally Posted by Spaz

most people don't even know to look for that...

That is the key word.....

**Spaz** · 12-02-2009, 06:11 AM

Originally Posted by SOMbitch

That is the key word.....

probably around 95% of people don't know to look for that...

**SOMbitch** · 12-02-2009, 06:37 AM

I got checked for air/egr the first year I had my car(bone stock). The guy looked my car up in a book to see what it was supposed to have. Last year year got turned away by 3 shops cause my car was to low to get on their lifts (and they were to lazy to use a floor jack) until I found a garage that would take my word I had cats. The car has emmisions headers but I don't remember if they checked that stuff.

Point is they are pretty strict here in NC. The first guy I went to I knew. I said "c'mon, you know I'm not the man." He said "but the man might be sitting over at Taco Bell watching me inspect your car." The State sends people around to inspection stations with various things wrong and try to bust people here.....

But you are right 95% of the guys don't look for air/egr but more look for cats.....

**Spaz** · 12-02-2009, 06:55 AM

Originally Posted by SOMbitch

I got checked for air/egr the first year I had my car(bone stock). The guy looked my car up in a book to see what it was supposed to have. Last year year got turned away by 3 shops cause my car was to low to get on their lifts (and they were to lazy to use a floor jack) until I found a garage that would take my word I had cats. The car has emmisions headers but I don't remember if they checked that stuff.

Point is they are pretty strict here in NC. The first guy I went to I knew. I said "c'mon, you know I'm not the man." He said "but the man might be sitting over at Taco Bell watching me inspect your car." The State sends people around to inspection stations with various things wrong and try to bust people here.....

But you are right 95% of the guys don't look for air/egr but more look for cats.....

in my case (and anyone can use this) i dropped in a new engine (ls6) and there were no provisions for either... so they really can't fail you for it...