Hi all!

Brand new poster, new c5 owner. My 110k mile 2002 C5 is a bit of a project but I already love her.

A few weeks ago, I got a check engine light with a cat efficiency bank 2 code. I’ve cleared it a few times but it keeps coming back after ~40 minute drives, so it seems legit. I’ll be replacing the applicable o2 sensor in the abundance of caution, but I am pretty doubtful that is the issue. Cat seems much more likely (even though there aren’t any obvious external issues with it that I can see).

In any event, assuming I need to replace the entire midpipe, I’m trying to come up with a plan. The part looks to be discontinued and the used ones on eBay are more expensive than I’d like (I haven’t looked for long but $500 to $1000 seems like the norm). Which seems like a lot considering what I’m getting.

Here’s an example: https://www.ebay.com/itm/313732232121

The C5 is all stock at the moment, other than a cold air intake that a previous owner put on it. In theory I could use this opportunity to get started on an exhaust system for it. But I’m a little wary given the fact that this is my first project car and I’m trying to take things very slowly, and my first initial goal is to get it running well before transitioning into upgrades. The other wrinkle is that I need to pass emissions in order to register the vehicle, and the grace period expires in a few weeks.

What do you guys think? Is it a waste of money to find a used C5 midpipe with cats to keep things simple? How beginner friendly is installing an exhaust system? Are there any handy guides here?

Thank you!

 

Welcome!

First things first, are you located in California? Some of our responses might change if you have strict emissions testing requirements vs. somewhere without.

Not a waste to go used at all, IMO.
I'm in CA, and the midpipe that came with my 2001 Z06 had 2 cats that used to be CARB-legal but lost their approval status before I bought the car. This caused a visual check fail during my first SMOG check, and I had to overcome it. To do so, I bought a midpipe from a 2004 base C5 that had the appropriate 4 cats, for ~$350. Granted this was back some time in 2019.
Then last year, a guy who sold his 2002-2004 C5Z also had his old midpipe for sale for $150. It only has 2 cats, so I can't use it for passing a SMOG check, but is otherwise interchangeable on my 2001 Z06 (and I believe all 2000-2004 Corvettes).

VERY easy to swap midpipe in general, but a bit of a hassle due to weight. Just 3 nuts at each manifold, 2 bolts holding it to the front of the torque tube, 2 bolts at the rear where it's supported by spring hangars, and 2 bolts per pipe connecting it to the catback. The job only becomes "difficult" if any of the bolts/nuts/studs are seized.

 

If you're in a CARB emission state, you're stuck with a CARB approved midpipe. Meaning a stock used one or there may still be an aftermarket company that offers a CARB approved option, but they're far and few. If you need a stock pipe, just be patient and scour ebay, classifieds here, FB, etc. A lot of people want 500+ for them because scrappers will pay them that much. But with a little patience you can find another Corvette owner that's happy to support another owner and sell it for a reasonable price. There was even a guy on FB the other day that offered a new owner an entire exhaust system for free. There are still some good ones out there

If you're in a emissions-lax state, sounds like a good opportunity to thrown on some headers and a tune.

 

Thanks so much!! Should have thought about the emissions standards. My state did indeed just switch to CARB standards. So I think that makes the decision much easier. I’ll keep my eye out on Facebook, Craigslist, eBay and the like for a used pair of the pipes/cats!

This was exactly what I was looking for, so super appreciative to you both.

 

Absolutely. Both of us have been through the ringer in CA for this exact topic, so we're glad to share information that a lot of people don't have (fortunately for them...lol).

To piggyback on his mention of losing CARB approval for the cats he had, it's pretty important that you have a used midpipe that has the correct amount of cats yours had from the factory. Some had 2 main cats, some had 2 pup cats closer to the manifolds AND 2 main cats (4 total). You'll be fine most of the time, but if you come across an overzealous tech or have to go to the state referee, they'll not only make sure you have the correct setup, but the ref may also make you certify that the pipes on the car ARE the original ones that came on it from the factory...pretty ridiculous...

If you buy aftemarket CARB approved, check the actual CARB approval first to make sure your model and model year is included in that approval...I was lucky enough to buy an expensive Magnaflow CARB midpipe when I needed one, only to find out my model year wasn't included and I just wasted a boatload of money...lol.