California Emissions Question
Thread Starter
Instructor
Joined: Aug 2003
Posts: 105
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From: Macon GA
California Emissions Question
Hello everyone.
I am considering the purchase of an 88 Corvette with RPO NN5, the dreaded California Emissions Requirements code.
Now, the question is: What is this RPO comprised of and how hard is it to get rid of the extra equipment? I live in central Georgia and do not have to put up with emissions testing at the moment and cannot bear the thought of anything keeping the engine from performing to it's fullest, so anything extraneous must go. Thanks in advance for your help.
Justin
I am considering the purchase of an 88 Corvette with RPO NN5, the dreaded California Emissions Requirements code.
Now, the question is: What is this RPO comprised of and how hard is it to get rid of the extra equipment? I live in central Georgia and do not have to put up with emissions testing at the moment and cannot bear the thought of anything keeping the engine from performing to it's fullest, so anything extraneous must go. Thanks in advance for your help.
Justin
Team Owner
Joined: Dec 2000
Posts: 90,675
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From: SE NY
Cruise-In II Veteran
The only thing NN5 did was lighten your wallet.
It paid for CARB extra testing but entailed no added emissions equipment.
My '88 is a ca car and so also has that "paperwork" option.
It paid for CARB extra testing but entailed no added emissions equipment.
My '88 is a ca car and so also has that "paperwork" option.
Racer
Joined: Jan 2005
Posts: 312
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From: Las Vegas / Scotland
So the air pump and the header air injection system are on all Vettes of that year then?
My 88 is a CA car with NN5 however it cost a phenomenal $99 in 1988 so I guess it couldn't have paid for much equipment at that price LOL
By the way I understand that it is a Federal offence to tamper with or remove any emission equipment that was fitted at the factory regardless as to whether your state requires it or not. Not that we would of course
My 88 is a CA car with NN5 however it cost a phenomenal $99 in 1988 so I guess it couldn't have paid for much equipment at that price LOL
By the way I understand that it is a Federal offence to tamper with or remove any emission equipment that was fitted at the factory regardless as to whether your state requires it or not. Not that we would of course
Team Owner
Joined: Dec 2000
Posts: 90,675
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From: SE NY
Cruise-In II Veteran
Well there are some exceptions, which include cat replacement.
For example, if the age and condition of your cats warrents it, it is 49-states legal to install a pre-catless front Y replace the main cat with a 3-stage main cat.
Since I have to pass the e-check in OH, this is exactly what I did with my '88. The change, along with a hi-flow cat-back, netted close to 20hp at the crank and easily passes emissions testing.
For example, if the age and condition of your cats warrents it, it is 49-states legal to install a pre-catless front Y replace the main cat with a 3-stage main cat.
Since I have to pass the e-check in OH, this is exactly what I did with my '88. The change, along with a hi-flow cat-back, netted close to 20hp at the crank and easily passes emissions testing.
Race Director
Joined: Aug 2003
Posts: 11,043
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From: San Jose Pat Tillman - American Hero
Originally Posted by stevec4
By the way I understand that it is a Federal offence to tamper with or remove any emission equipment that was fitted at the factory regardless as to whether your state requires it or not. Not that we would of course
Burning Brakes
Joined: Nov 2003
Posts: 914
Likes: 1
From: Redding Ca
I think the biggest issue we in Ca have to deal with in smog compliance are those darned pre-cats. In order to pass the "visual" inspection along with the bi-annual tailpipe inspection, is we cannot have long tube headers even if they have emissions equipment (such as all same year F-bodies, no precats and LT headers are EO approved). 
How we pass the bi-annual test and still have hi performance is known only to God and possibly to a priest if one is Catholic
How we pass the bi-annual test and still have hi performance is known only to God and possibly to a priest if one is Catholic
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Burning Brakes
Joined: Nov 2003
Posts: 914
Likes: 1
From: Redding Ca
I believe pre cats are all '88 Vettes. Any state that says we cannot change the original smog equip without something similar to a CARB EO# means you are stuck with leaving them on if you want to be legal. I know at least one forum member in Ca who is tightrope walking this issue by using shortie headers with emissions equip in order to retain the pre cats. (some of us really do care about air quality) 
. I do not know whether he has been through the smog inspection yet.
The good news is he has a gorilla engine and still expects to pass the tailpipe test with room to spare (maybe only a little) by careful selection of parts (AFR 195 heads and Super Ram have Ca EO#'s). But my point is, it is the visual he is concerned with so he is trying to comply.
. I do not know whether he has been through the smog inspection yet.The good news is he has a gorilla engine and still expects to pass the tailpipe test with room to spare (maybe only a little) by careful selection of parts (AFR 195 heads and Super Ram have Ca EO#'s). But my point is, it is the visual he is concerned with so he is trying to comply.
Team Owner
Joined: Dec 2000
Posts: 90,675
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From: SE NY
Cruise-In II Veteran
Well CARB is not really about clean air, but rather about compliance to the "letter" of the law. If the sniffer shows low enough levels of emissions it should not matter how that is achieved.
My '88, with no pre-cats, a 3-stage hi-flow modern cat, running a 160deg T-stat & fan switch in the middle of Feb. easily passes the OH dyno sniffer test.
OH is one of the many states that is concerned about clean air but is not overly pickey about it. Their sniffer test is a stringent dyno test at various speeds (much like AZ) but if your vehicle passes and has a cat you are good to go, as it should be.
A work around in CA might be to install a mandrel bent front Y and simply weld the pre-cat shells onto it so it would pass a visual. With a good hi-flow main cat and AIR equipment the L98 would pass the sniffer.
My '88, with no pre-cats, a 3-stage hi-flow modern cat, running a 160deg T-stat & fan switch in the middle of Feb. easily passes the OH dyno sniffer test.
OH is one of the many states that is concerned about clean air but is not overly pickey about it. Their sniffer test is a stringent dyno test at various speeds (much like AZ) but if your vehicle passes and has a cat you are good to go, as it should be.
A work around in CA might be to install a mandrel bent front Y and simply weld the pre-cat shells onto it so it would pass a visual. With a good hi-flow main cat and AIR equipment the L98 would pass the sniffer.
Team Owner
Joined: Sep 2003
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From: Freedom is never more than one generation away from extinction.
St. Jude '03 thru '24
IMHO.....NN5 is the option to move money from the General to PRK. 
CARB is all about money. Test your car and take your money. If you fail the test, pay more money. If Kalifornia was really worried about air quality, they would slam fines on the single occupant commuters in the big cities and divert the money to building mass transit systems.
But alas, they can get additional revenue by adding "NN5" options on all cars. Its a taxable tax. The perfect perpetual money machine.
CARB is all about money. Test your car and take your money. If you fail the test, pay more money. If Kalifornia was really worried about air quality, they would slam fines on the single occupant commuters in the big cities and divert the money to building mass transit systems.
But alas, they can get additional revenue by adding "NN5" options on all cars. Its a taxable tax. The perfect perpetual money machine.
Drifting
Joined: Aug 2004
Posts: 1,400
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From: Oceansaide CA
..or find a guy who's not an anus when it comes to visual 
I'm getting a catless y-pipe, and later a whole new rear y, with a fresh 3 stage main cat (I used to run 2 diff exhausts on my cars, 1 for smogging, one for always until I started feeling guilty about killing seals for 5 extra HP
)
I'm getting a catless y-pipe, and later a whole new rear y, with a fresh 3 stage main cat (I used to run 2 diff exhausts on my cars, 1 for smogging, one for always until I started feeling guilty about killing seals for 5 extra HP
)
