Secondary Cat delete

Obviously living in California, and been thinking about removing the 2nd set of cats. I know, the 02 sensor is in front so shouldn't throw a code, but the question- would I still pass smog?

thanks dudes

 

would you gain HP

 

doubt I would feel a difference in throttle response, more after the noise.

 

Hmmm... I really wonder if I wouldn't pass smog, no sensors in there. Okay, if all fails I'll just delete the muffler(I know I know, 'back pressure man, you'll lose all your torque!')

3" glass, so they're straight through with perforated padding or something surrounding?

 

Thanks Colton, I just repped you.

Agreed on #2, and honestly I wouldn't ditch the muffler, especially since I just bought it. I made the comment on the torque and backpressure cause I think it's over rated and misconstrued by most. The results are negligible no doubt.

So that's what those secondary cats do, burn the extra fuel. Excellent info, now if anybody in California could chime in on this.

 

Do it

 

Open it up too much and u will notice the tq down low go bye bye.

Over rated maybe sometimes........ but under rating it is a slap in the nutz, and wallet if u go overboard n/a

 

"smog" depends on where you are at, here it TX it is basically an OBDII connection, no codes = pass. In this case removing the rear cats will still pass. In CA I have "heard" that they also do a visual, in which case you would fail.

 

But are the second set really cats or just resonators? I have wondered this since day one.

PK

 

Your car has to have ALL the emission components that came with it(or some CARB approved variation of it), stock. You cannot, however, permanently remove any emission component and still pass smog. Im a smog tech in cali.

 

You said you didn't know how they check smog in California. Don't take my word for because I don't live in California but I thinks they put a sniffer in the tailpipe and check how much hydrocarbon (gasoline) nox and carbon monoxide gases are coming out of it. In my opinion I wouldn't do it because I hear California is strict on there emission laws.

 

Just put a cat on I mean your cats are mostly dead from taking all those poisonous gases for your truck

 

i know this thread is old but i hope ill get a reply. if i remove the back 2 cats i will NOT get a check engine light correct?

 

also i'm not worried about smog or loss in low end torque

 

Correct. No check engine light.

 

ok thanks

 

Any thoughts on if this will result in more exhaust pops and crackles due to the secondary cats not being there to remove the last of the unburnt fuel? I have just a basic muffler delete, and you can make it crackle in 1st and 2nd when you let off the throttle between 2500-2750 rpms and feather the gas.

This forum is only 5 years gone, psh.