gimp

I'm in a bit of a pickle. I may need to return a C5 exhaust system to stock. That means replacing long-tube headers and cats back. I am hoping that putting them to CARB-legal may be enough, but it's possible I might have to put them back to complete factory stock.

The short story is: I'm interested in a forum member's supercharged C5, but it has no sticker. Called up Magnuson and they say that to get a new sticker, the headers have to be stock, and they need to reprogram the computer, and it has to be done through an official GM dealer. (Well, I imagine that I can return the headers to stock myself - I'm handy - or pay a less expensive shop; then have the stuff reprogrammed through the dealer, saving on labor costs.)

All to pass California emissions. (SF bay area.) I don't particularly feel like finding a "friendly" shop to the tune of $400++ every two years..

Can anyone give an estimate to the lowest cost to get such a setup to get certified and pass smog?

I'm not really against the idea of changing the system *back* to the long tube headers, as long as I can do it in myself with about a day's worth of work, every two years; so I'm looking more for cost than CARB-legal performance.

Thanks a ton.

I tried googling a bunch but nobody ever cares about restoring these to stock, so I couldn't find the answer.

leadfoot4

I would start by checking the "parts for sale" section here, to see how many of the stock exhaust components you can find, then go from there.

73Corvette

gimp

Stupid - I should have searched here. Found someone selling stock headers and cats with extras. Hopefully this will be enough.

Looks like it's a full day's worth of work to swap the stuff, and another day to swap back... I might be able to do it myself, which will save a lot of labor cost.

Anyone know how much labor hours it would take a shop?

Thanks.

leadfoot4

I would think that it would depend on whether or not your headers need to have the engine lifted, in order to slip in and out. I know the OE manifolds can be removed in an hour, or so, once the car is (safely) up on ramps or stands. I've had mine off, to remove excess material and casting flash in the ports.

Once those are off, or the headers, in your case, I would think the mid pipe shouldn't take more than another hour, then maybe 3 hours to replace the parts that have been removed.

The real time consumer, most likely, will be the re-installation of the headers. Having some extra hands available, would be very helpful, and don't forget to use anti-seize on all of the threaded fasteners.

vettenuts

What about the programming? If a dealer over writes the tuning you now have, will it impact the tuning when you re-install headers? Any other after market parts?

Chris0810r

I have stock manifolds and h pipe off my 40K FRC we just removed for a LT and X pipe install. All in mint condition, little to no rust and Speed Inc block offs in the AIR injection.
Will sell cheap, unfortunately I am in Chicago. PM if interested I can send pics.

Stroker87

you can save the current tune file, have the car tuned for stock then when you put every thing back on just reload the tune for the mods, it does not have to be put back on the dyno long as every thing is going back on that was on the car when it was dyno tuned

most tune shops have stock files

gimp

The car also comes with an autocal, so I shouldddd be able to get the tune back.

However, in the spirit of proper corvette ownership, I may modify some stuff enough that I'll need a proper tune from a performance shop in the area. We'll see.

I'll make sure to use anti-seize on all the fasteners, thanks for the advice.

Currently it has long tube headers, which is going to be a right pain to uninstall and later reinstall if I feel like flaunting california law.

Bill Curlee

If you have AUTOCAl, I would contact Chuck at Corvettes Of Westchester. He can help you get the tune saved and the stock files up-loaded and installed. Its easy to switch back in forth once you have the procedure down. He can also provide you ANY and ALL the additional tuning that you need later down the road!

You said stock headers. They are refered to as OEM Exhaust manifolds. NOTE! 1997-2000 use a couple different systems. as long as you have the ENTIRE exhaust system from one year car (exhaust manifolds and midpipe,, you should be good. 2001-2004 also have a couple different designs.

The Over the Axel mufflers are one fits all (ZO6 or LS1 any year )

If CA requires PUP CATS, you will need to find manifolds and a mid pipe that incorporates those:

MID PIPE WITH PUP CATS at the inlets:









Bill

gimp

Hum... I have no idea what pup cats are, and google is mostly telling me about animals. I mean, I sort of figured out what they are, but I can't figure out their official name, hah!

If the 2003 didn't come stock with pup cats, then I don't think I need 'em.

Bill Curlee

In the picture I posted, the Bulges just behind the pipe inlets are the PRE-CATS and YES,, some CALI Cars had that exhaust midpipe installed if the car was to be registered in certain states. Some people call them PUPCATS.

SO,,,,, before you purchase a system, I recommend you research what your car has to have to be compliant.

I would go ask and or research what was required for your year/model C5 for Cali.

gimp

I swear to god, I hate california car smog laws. They make no sense, except to extract money.

Pre-cats seem standard on a 2003 model: https://www.corvetteforum.com/forums...ls-within.html

I might skate by without this by getting the 2000 pipes without pre-cats. I might not and end up wasting a few bucks. I think I'll take the gamble; we'll see.

Smoken1

Where in CA are you? I have them coming off my 02 vert

gimp

SF bay area. How about you?

Smoken1

Exit 113 off I5 near Roseburg OR

gimp

Oh, fun road trip!

I don't know your timeframe - but if the ones I'm planning to get don't pass, and you haven't sold yours, I'll probably drive up and collect them. Might borrow a friend's truck, dunno how well they're going to fit into my buick.

Do you know when you're planning to take yours off and put them up for sale? Mind if I PM you at that time?

Obviously I'm hoping I won't need yours, but ...

Smoken1

Just so you know it has the Magna flow X pipe on it. Still passed emissions..Pm me if you want

93Polo

I would also look into a C6 LS7 system

https://www.corvetteforum.com/forums...on-a-c5-2.html
https://www.corvetteforum.com/forums...t-on-a-c5.html

Post 4: "I did get the C6 Z06 exhaust fitted to my C5. Several here in Cali have done this due to emissions restrictions. Gains approach what a set of LT headers deliver."
https://www.corvetteforum.com/forums...fit-in-c5.html

tlove32

It cost me about $500 in parts and $500 for labor and re-tune to go back to stock(ish) and get C.A.R.B legal. I also sold my LT headers for $700...so all-in-all...I was only down $300