Hello everyone,
This will be my first post on this forum, so I apologize in advance if this has already been brought up.

I recently bought a 1997 LT1 from a guy who did a bunch of things to the car, but now it no longer passes smog, and shows codes. I hope you all can give me some advice on how to get this thing back to stock so I can legally smog it and register it under my name. I am talking about CA smog, so visual is important as well.

1. It seems the previous owner put corvette valve covers on the engine. These have 2 holes in one valve cover (PCV and oil cap), and 1 in the other (PCV?). Right now there are just 2 breathers in the PCV holes, and of course an oil cap in the 3rd hole. Obviously PCV breathers will never pass smog, so I'm trying to figure out what to do with these. I know passenger side valve cover should have the PCV hole connect to the throttle body (right now this hook up on the throttle body is uncapped!)

From what I read, the passenger side valve cover hole isn't exactly PCV, and serves as a fresh air hole for the MAF. Does this require a special PCV (or whatever you want to call it) that fits into the valve cover?
Once fixed, can I expect the engine to run a bit better now that the MAF is connected correctly?

2. Should the hole in the driver's side valve cover even be there?
I know the PCV on the LT1 engines is located in the intake.
Should I run a T-fitting and connect the PCV holes from each valve cover to the throttle body?
Should I just plug this hole?

3. The previous owner also installed BBK headers. I believe they are considered midlength, and they do have the smog tubes on the them. How can I be sure they are legal or illegal? I know there should be a CARB sticker somewhere, but where should I check?
Seems like if they put a sticker on the header it would just burn off. Is the CARB sticker ever engraved? on the header?
It looks like the previous owner welded the headers directly onto the downpipe and CAT, so at least those are still there, but not sure if these would ever be considered legal.

Thanks,
Adam

 

The PCV valve is located on the driver's side, side of the intake manifold. The vacuum source for the PCV valve in on the front of the intake manifold, below the throttle body. Shoebox has good photos:

http://shbox.com/1/pcv.jpg

http://shbox.com/1/pcv_pipe.jpg

While it doesn’t appear to make sense for a vacuum port on the front of the intake to pull vacuum on a valve on the side of the intake, it actually does make sense. At least once you understand the PCV valve does not connect to the plenum, but to a passage from the bottom of the intake manifold, that pulls crankcase vapor out of the lifter valley.

The plumbing on the passenger side of the engine is there to supply fresh, filtered air (that has been included in the air measured by the MAF sensor) that flows through the crankcase, and sweeps the crankcase blowby into the lifter valley. On an F-Body LT1, the clean air supply line comes from a port on the throttle body (that supplies air from in FRONT of he throttle blades, where there is no vacuum) and runs to a plastic elbow that pushes into the grommet toward the rear of the passenger valve cover. There is no PCV valve there.

The F-Body LT1 does not have any openings in the driver side valve cover.

The headers require a metal tag welded to one of the header primaries, with the CARB-EO exemption number. CA has a website that lists CARB approved aftermarket components, but it is hard to navigate. The determining factor is that the headers cannot require relocation of the stock cats. That's difficult with the driver side stock cat bolted directly to the outlet flange of the exhaust manifold. The typical CARB approved 96/97 headers wrap the primaries upwards, over the valve covers, then back down so the header flange so the cat is in the stock location.

 

OP

get a set of stock valve covers and then buy the hose for the PS that runs to the TB. It not a PCV valve. There should be no hole in the DS valve cover. If the motor has roller rockers, other than Crane Gold "narrow body" you will need to trim the drip baffles of stock valve covers to fit which is no big deal and easily done. Golen engine service has the pic how to in their tech article section

If the BBK don't have a model # stamped into a welded on plate, typically on DS header, AND a CARB sticker noting that model # along with the CARB # than they are not CARB "compliant" and you will fail visual. IIRC Edelbrock and SLP shorty headers were the only ones that came with a CARB sticker. I have the Edelbrock and have a CARB sticker on core support for them

CA emission requirements say the CATS have to remain within 3" of their stock location

You may also have a "performance tune" in the PCM which "may" be OK in terms of tail pipe emissions but aggressive tunes (fueling & timing) can push emissions past acceptable levels especially if the motor is either poorly operating (because of vacuum leaks, fueling, etc) or is just worn with blow by than that can also compound being able to pass emissions and would require those "mechanical or tuning" issues to be resolved

With all this said you can have a 383 H/C motor with CARB shorty headers pass CA smog if you have the correct tune and a solid operating motor

BTW, in CA the seller is responsible for providing the buyer with a smog cert...