Punching out cats.

CManT1914

New Member
Feb 5, 2004
3,172
2
0
Killeen, Texas
Starting here in January 2005, Texans will be require emissions checks when getting your car inspected. At least that's what my mechanic told me. Since I was about to do an O/R h-pipe, he said I could get BBK hi-flow w/cats, and take a long screwdriver and hammer and just punch through the cats. Anybody done this, is it hard to do? It's gonna be an h-pipe for shorty headers.
 
Paying so much for aftermarket H-pipe with cats only to "punch through the cats" seems odd IMO.

I'd say keep the high flows on, it will make emissions easier and won't gob up THAT much power compared to stock H-pipe? Or just gut the stock H-pipe...
 
stockhatch said:
I agree. Why pay all that money for aftermarket high flows to punch them out?! Just buy and off road H and swap it out for the stocker during inspections.

AC

Because I'm freaking lazy that's why. LOL, seriously though, I don't want to have to pay twice as much just to knock through them, but it would make getting inspections a HECK of a lot easier.
 
After looking at your sig, Hi-flow cats or no cats isn't going to make much difference in HP. If you had heads, cam, & intake mods in a no smog area, a cat less H pipe might make sense.

If you have to pass a sniffer test, no cats or cats that don't work greatly shrinks the probability that you will pass.
 
jrichker said:
If you have to pass a sniffer test, no cats or cats that
don't work greatly shrinks the probability that you will pass.

The way I understood it, was that the inspector was only required to look under the car to see if there were cats on your setup. They don't have to actually take a reading of your exhaust or whatever. So if I had punched out cats, then I should pass no problem. But then with the O/R I think I would need the MIL plugs. That's another $50 right there!
 
mil plugs aren't for pushrod motors. If you are sure they wont sniff, punchout your stock ones. Or like sleeper said, swap them out once a year. Your choice, but I agree that I wouldn't pay big bucks for high flow cats just to ruin them. You may gain a hp or two with you mods. Not worth it in my opinion.
 
rdksek844 said:
mil plugs aren't for pushrod motors. If you are sure they wont sniff, punchout your stock ones. Or like sleeper said, swap them out once a year. Your choice, but I agree that I wouldn't pay big bucks for high flow cats just to ruin them. You may gain a hp or two with you mods. Not worth it in my opinion.

Well I'm gonna go with some equal length shorties and the O/R h-pipe, or maybe just punch out the factory ones. I'm as concerned about gaining horsepower as I am about getting a mean sounding exhaust.
 
T_5.0_N'works said:
I'am in SA and there is no emmisions testing right now or even word of it coming yet. Dallas and Houston do though. God Bless Texas.

Is the inspection thing a city-ordinance, or is it controlled by the state? In other words, does the state of Texas require emissions testing, or is it just the city of Dallas, Houston, or wherever?
 
CManT1914 said:
Is the inspection thing a city-ordinance, or is it controlled by the state? In other words, does the state of Texas require emissions testing, or is it just the city of Dallas, Houston, or wherever?

What I think happens is air quality is measured and if it's past a certian degree of 'dirtyness' Texas requires cat testing then. SA is still clean but it's kind of on the verge, been like that for a few years.