I'm going to be getting longtubes for my 96 Z28 by this spring at the latest.. Probably the Pacesetters, and I'm trying to figure out how to pass emissions.. I was hoping to go without an offroad y-pipe and no EGR or AIR.. I was considering putting a gutted cat behind the y-pipe just for looks at inspection, although I'm not sure if they'll even check.. Not worth the risk though I figure.

What I need to know though, is if I go with O2 sims, will that avoid the code being thrown for not having cats? Then what do I need to do to avoid getting a code for EGR and AIR being removed? Is there anything aside from getting a tune that will do this? How much will a tune run me?

Last question, if someone doesn't mind explaining, what exactly do the EGR and AIR systems do? Is there any downside to removing them?

Thanks so much..

 

with a gutted cat and egr/air removed you probably won't pass.

 

Even with the sims? I don't get sniffed, they just plug in to the OBD-II...

 

o with the plug in and the o2 sims then you'll pass. As long as theres not SES light then it's all good as far as they know.

 

I am not aware of any CARB approved LTs. It's cuz they relocate the cats.
Relocating cats is a no no.......yes it's a stupid rule, but that's life. Not sure
about other states.

 

Plug in? You mean leave the EGR/AIR or just put the sims on? And what's CARB stand for? Is that California? I'm in Delaware...

 

CARB is a socialist republic of CA thing.

 

Since you don't take the smog test just remove whatever u want and get a tune to take the codes out, then no more SES light when u go to testing = emissions passed.

 

Great, thanks.. Is there any downside to removing EGR and AIR? Everyone seems to suggest it but I just wanted to be sure there were no negatives...

 

EGR = exhaust gas recirculation, there is a vacuum operated valve on the backside of the intake manifold that returns exhaust gases to the intake tract to be reburnt. I'm pretty sure this valve is only open when the engine is cold (before the cat heats up, this is when emissions are the worst) I blocked off the EGR pipe for a while and personally didnt notice any gain in performance. removing this wont hurt perfomance/driveability.

The air pump merely pumps air into the exhaust manifolds to reduce emissions. removing the air pump will do nothing for performance, but it wont hurt performance or driveability either.

 

Like said before they fail because the cat is moved from the original location....most of the headers are 50 state legal, which means they have all the neccesary hook ups.

 

Yeah, but the Pacesetters only come with an off-road Y-pipe.. So if I were going to put a cat on it would be behind it, and it wouldn't be a dual cat so I was going to just gut it instead of forcing it through a single cat.. Will they know the specific cat location from year to year and the Z28 as opposed to the 3.8L? I'm pretty sure the cat on my old 3.8 was about where I'd be putting the gutted one...

 

Not everywhere requires the cats to be in the original location, in texas I know its not a requirement atleast. Also drive the car 50-100 miles before you go get tested if youve unplugged the battery or reset the computer or the machine will read your sensors as not ready, if the sensors have not had time to reset you will fail. Just make sure the computer cant tell you dont have an egr or air system and you should be fine and just hope they dont have a picky inspector so they miss the stuff not being there Oh yeah and make sure you have good wiper blades, people get so upset when I fail them for that but its most often forgot.

 

the 96 and 97 LT1 Fbodies are OBD-II. Therefore they do not put you on the sniffer for emissions unless you fail OBD-II test. So as long as you send your pcm out to be edited for any codes, then you are fine, and will pass the OBD-II test. You will need to pick up O2 simms for the rear o2's though. I have heard that you get have them deleted out, but Im not sure if that would throw up a code durring the emission test.

Mike

 

Different for evey state - in Cali, they put you on the sniffer no matter what.