Passing Smog In CA - Catless Headers

Possible with stock exhaust and O2 spacers ?

As long as you have a tune that removes the check engine light.

Calfornia smog includes visual inspection of the cats. So if your shop does it correctly they will fail you on the visual, regardless of what the OBD2 says. For the record, removing cats on a street car is a real jerk move.

So, is Gubi the "record" keeper? Didn't know we had one of those on this site.

It also depends on the test the state performs - some will pass an uncatted car with a tune that turns off the second O2 sensor monitor; some states (I bet California is one) have more stringent tests via the obd2 port that can sense that the secondary O2 monitor is not in "ready mode" ie turned off. You can either just reinstall the factory headers (much easier if you use studs and nuts and not factory bolts) or use the Cargraphics modular headers that have a cat that can be removed and replaced with a straight pipe. Now for my soapbox moment - for all of the greenies that are so uptight about the cats being removed, get a grip, it does not produce enough co2 to move the needle; the electricity that has to be generated to charge your electric car creates more co2 emissions that any single vehicle can.

Now that you've had your soapbox moment, the point of catalytics converters is to produce CO2 rather than alot of Carbon MOnoxide, NOx, and unburnt hybdrocarbons. Your greenhouse gas argument against uptight "greenies" doesn't make for a great soapbox moment. If you live and drive primarily in a highly populated urban/suburban/exurban area in CA, driving around without cats is kind of a jerk move because of the stink you cause and CO people have to inhale everywhere you drive more so than anything else. At this point, catless cars aren't a big enough problem for one person running without cats to make a dent in smog and air pollution. Practically speaking, unless you know somebody and/or are willing to grease some palms, AND haven't been referred to a STAR smog station by your DMV notice, you aren't going to be able to pass emissions in CA with catless headers .

Not just Cali, where I live they do the "sniff" annually at registration renewal. Unlike ye olden days in NY where my inspections were visual mechanical, the car has to connect to the state computer. I can't see how the guy could take a bribe if he wanted to. Therefore, you would have to remove and replace annually if you believed the cat removal was a huge difference. I used to own a Cosworth Vega, I had a "test pipe". Without the cat is was annoyingly "I'm sure neighbors hated me loud" but I'm not convinced it was noticeably quicker. I will say this, although a Vega in every other way the car was a rocket (relative to the time it existed) with those heads on it.

Thank you all for the responses. I have several reasons for running catless headers , the main reason of course for performance. However I’ve also heard of issues running with catted headers , clogging issues or cel issues which I refuse to deal with given the current price or oem catted headers . Also it’s my understanding stock exhaust has a second pair of cats and I’ve read of people passing after proper warm up. I’m merely reaching out for solutions that could help me navigate through this complicated mess of CA regulations while minimizing cost and maximizing the potential of our engines.

Legally there's pretty much nothing you can do to the cats or headers in California. Any emissions part installed needs to be CARB certified and have an EO number stamped on it. None of the aftermarket headers or high flow cats (and especially not a cat delete) are gonna be legal. Cat delete is also illegal on the federal level, so that's not just CA. You mod it, you're going to have to risk it every time you get it smogged. It's pretty hard to hide aftermarket headers and missing cats and O2 sensor spacers. The legit smog guys like keeping their jobs, so they'll do it properly and inspect the cats and then flag it, and then you're hosed. And even if you can find a crooked or blind smog guy for the whole time you own the car (which I do not suggest doing) then someday in the future you're going to have to deal with the issues of selling a non-smog-legal car in the state. My advice would be to leave it stock: don't cost you nothing, you can sleep easy that way, and modern cat converters flow pretty well and really don't cost you that much power. (Plus you won't be a jerk)

+1 on keeping stock headers . If you absolutely want to swap it out, one option could be 200cell headers . Carnewal keeps the stock look (over anyone else) so you will pass visual inspection. Check around if this will let you pass CA smog tests or not, you can also reach out to Gert at Carnewal . 987-1 Cat upgrade 200 cell - Carnewal For me, 10HP is not worth all the trouble as I drive the car mostly on the street so far.