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Kiss my shoes
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4 Posts
Discussion Starter #1
So I’m on my last leg in passing this ca smog
I have long tube headers cams heads tuned ..

And I keep hearing a bunch of different stuff in what I do to pass it
Today I’m suppose to head to Chevrolet to retune my car back to stock they said $200 an hour and can take up to 3 hours . By me doing this will I pass smog . I have a smogger that will pass my visuals
I have my cats and mufflers any feed back will help tons
 

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The Grinch
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3,027 Posts
Dude. If you have an aftermarket cam in there and you put stock tune in there you will get worse emission results than now. If you have to pass sniffer test. Any cam with any overlap will fail.
 

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Kiss my shoes
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4 Posts
Discussion Starter #3
Thank you for your feed back I’m new to this and trying to figure out my options I would hate to spend money and it not work out any suggestions? Am I not going to smog and have to put my stock cam back in had some tuners say
If I put my stock
Tune back on they can pass it 🏽🏽
 

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Rockin the Bakken
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319 Posts
Dude. If you have an aftermarket cam in there and you put stock tune in there you will get worse emission results than now. If you have to pass sniffer test. Any cam with any overlap will fail.
All cams have overlap. You're speaking of overlap at 50 thousandths?
 

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Registered
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574 Posts
So I’m on my last leg in passing this ca smog
I have long tube headers cams heads tuned ..

And I keep hearing a bunch of different stuff in what I do to pass it
Today I’m suppose to head to Chevrolet to retune my car back to stock they said $200 an hour and can take up to 3 hours . By me doing this will I pass smog . I have a smogger that will pass my visuals
I have my cats and mufflers any feed back will help tons
Strictly speaking, a car with long tube headers will NEVER pass a smog check in California. Part of the test is a visual inspection, which would note that the catalytic converters have been moved (if they are even still there), which is an automatic fail on the test. You might get lucky and find a smog tech that will not look too closely. The tune also needs to deal with the rear O2 sensors that may set a code for catalyst efficiency even with cats installed.

California hasn't used the "sniffer" on late-model cars in a number of years. The test is limited to plugging in to the OBD2 port under the dash and letting the car run.

In short, if you want to pass a smog test legally, you would need to swap back to manifolds and stock cats. If the cam specs are too extreme, you would also need to swap to one that is closer to stock.
 

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Administrator
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7,995 Posts
That and depending on how wild the cam is, the car may not even run on a stock tune.
 

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150k Club
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3,955 Posts
If the o2’s don’t trip your cel and the tech is going to pass you visually you should be good.
 

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Manufacturing Engineer
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130 Posts
I know of a 2005 (not mine of course) with a 6.2, LS7 heads, LS7 intake, big nasty cam with 21 degrees of overlap, long tubes, cats and REALLY loud exhaust that passed without issue. This was also at one of the "Star Approved" stations, but he has been taking all of his cars there for the past 15 years so he knows him fairly well.

The car was tuned with HP Tuners and can set pretty much any code to "not report" and therefore a CEL or failed emission test will never show up. A stock tune will not do you any good if it fails any of the tests.

Find a good tuner or learn it yourself.

There is no tail pipe test for a 2005 GTO in CA. Only plug into OBD2 to check for emission test completion and CEL. Keep in mind, if you re-flash your tune, you will have to drive it for a little bit to complete some of the emission tests.

I believe the only test that you are allowed to have a "not completed" status is EVAP emissions, and no tests can show as "failed".
 

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Registered
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[QUOTE
I believe the only test that you are allowed to have a "not completed" status is EVAP emissions, and no tests can show as "failed".[/QUOTE]

This is correct, I can corroborate it. I had my 2006 GTO smog checked today at a local place here in Long Beach- engine is 100% stock and my car passed, even though my EVAP test was still incomplete. (My battery was disconnected a few weeks back and it still hasn't cleared yet.)
 

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Registered
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77 Posts
So I’m on my last leg in passing this ca smog
I have long tube headers cams heads tuned ..

And I keep hearing a bunch of different stuff in what I do to pass it
Today I’m suppose to head to Chevrolet to retune my car back to stock they said $200 an hour and can take up to 3 hours . By me doing this will I pass smog . I have a smogger that will pass my visuals
I have my cats and mufflers any feed back will help tons
Just wanted to note i had my PCM reflashed to stock when i was having issue with a "mail order" tune with Diablo. The tune file i was pulling was showing corrupt on his end and insisted i needed to be reflashed by GM.

I had it reflashed by GM in Rockville Center NY for 50$. He told me it was 100$ an hour in labor when i called and when it was done he said, it only took about 20 minutes so we are only charging a half hour.

Sounds like that dealer is ripping you off big time.

ALso later found out it was a an issue with my diablosport so im glad I didnt waste too much at the dealer.

Anyone with HP tuners can put that car back to stock tune, dont need a "600$" job done at GM. Lots of good advice on passing in Cali above though. My car was tuned with HP tuners to not report any O2 issues to pass emissions.
 
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