z06 Rules

Has anyone passed California smog with LG pro headers?? I just installed one with the cats that comes with it and put 02 sims. So there is no check engine light. But it failed the sniffer. The CO and NO values were too high.

Has anyone passed it in Cali and ho did they do it?

Thanks in advance............

vms4evr

I don't live in the Peoples Republic, but...

After you installed the headers did you get the car tuned? The computer is not set for LTs with high flow cats. A little tweaking maybe all you need. Plus you can do a dyno pull while you're there ;-)

BlackZ06

From the LG website ...

Note: Long Tube Headers are not CARB certified

see: http://www.lgmotorsports.com/catalog...oducts_id=1432

From what I know about our Byzantine smog laws, even if the car passes the sniffer test ... you are still "illegal" with these on the car ... any mod to the engine/intake/exhaust MUST have a CARB (California Air Resources Board) sticker (certificate) to pass an emmission test in Cali ...

Sorry ... I hate this as much as you do ....

69dodgecharger

even if you got around the visual wich ususally isnt hard to do since people are too lasy to look under corvetts (they are low) the high flow cats will not pass the sniffer.

TM-Z06

You need to remove the O2 sims, and have it tuned - that'll fix your problems.

z06 Rules

Thanks a lot for all of your input. I know the LTs are always illegal atleast in Cali but the reason I asked is because I know a lot of folks have them and have passed smog.

I think a tune is in order...............

gasboy

sorry to hear that your car failed.it is unusual for a car to fail on both co and nox.high co almost always means low nox.we put alot of o2 sensors in for co failures and always warn the customer that there may be nox trouble after that.i thought ca.did obd2 testing.how come you were on the dyno? good luck in getting it repaired.a tune will probably do it.

BlackZ06

The normal Cali test includes the following ...

1) Visual inspection
2) Connect test computer to car's OBD connection (this ensures that the VIN being tested matches so you cannot substitute another vehicle for the test, and checks for DTCs)
3) sniffer probe put in tail pipe and car run on dyno while the test computer is still connected to the ODB port. Car is tested at idle and at about 2000 RPM in this sniffer test.

This is pretty much the standard test in counties in and around metropolitan areas here in CA. Hard to beat the test if the car has "illegal" mods because the car is hooked to the test computer (which monitors and reports the VIN) for the entire test cycle.

I'm sure there are ways around the system if you know the "right people", but for the average Joe the system means that your car either passes, or not. And a no-pass means no registration .... kinda putting a damper on one's fun with the car.

socal guy

i agree a tune would help....

you will gain some HP and should pass the sniffer.

FYI....

i passed the CA sniffer with my 400rwhp 99SS.
it had a 222/224 .566/.568 114 cam, and ported stock heads,
LT's, high flow cats, LS6 intake, etc....

my smog tech said it passed no problem.

Skinny Kid

My car barely passed the sniffer, even with the cam. I just got the cats nice and hot before I ran it and all was well.

Justin

bobgodd

I agree with the cats. A high flow cat won't pass in CA. Just experienced this on my friends Z28 a couple weeks ago. Get real cat's on there, and make sure they're nice and HOT and the car should pass no problem. As long as the smog tech is willing to look past the lack of CARB Exemption number that is...

forsvette

Not really a fair comparison but I passed the CA smog test with headers, 3" exhaust and high flow cat on my 5.9 Grand Cherokee no problem. It can be done.

Mike