That's a good point, maybe it would just throw a code. If it doesn't effect anything in a negative way I could deal with that

 

It will sometimes put the engine into a run cold mode or otherwise fool with air/fuel.

Seriously, this is a lot of work just to be louder. Can't you buy a whistle for a sparkplug hole or something?

History Safety Signal Spark Plug whistle... WTF?? - THE H.A.M.B.

 

The downstream o2 sensor is there to tell the computer if the cat is working. It's a calculation of the difference between the upstream and downstream. Computer uses the upstream to adjust fuel so it will run fine, but you will have a CEL if there is no cat between the 2 o2 sensors.

 

X2 Great and spot-on accurate info right there

 

What is a CEL?

 

Also, it's not just the to make it louder, I heard it can give more you power and make the motor run more efficient. But it would be really nice to hear that flowmaster rumble.

 

You mean the Flowmaster drone, right?

Check Engine Light. The computer will set a code and turn a light on on the dashboard. You will also fail smog with a CEL on.

It will also go into limp-home mode, run rich, and other problems will ensue. See the below note:

Yes, you do and see above.

Yes, you can do it. You'll have the CEL come on and the truck will run like crap.

Should you be caught operating a cat-less vehicle in CA, they will impound your car (at least $300 to get it back, then you have to have it towed to a repair shop) plus a $2500 fine. This is also a criminal misdemeanor in the Gaia-worshipping state of CA, so you might be spending some time in jail, too. Each time they bust you.

Best part - trucks are really easy to look under, so cops in CA often make a point of looking. After all, it's a 'free' bust if they pulled you over already. There are also cops with smog sniffers out there (assuming they don't smell you running catless with their nose, which they can) so you can get tagged very easily.

This.

Reputable free flow cats will not make you fail smog, just the cheap crappy ones.

Yes, you need to replace all the cats in the system to remove flow obstructions.

 

Move to the Midwest we love loud dirty trucks and tractors

 

Oh and you can run one cat with no codes as long as you keep the front one

 

Amen! That's why I love living in the middle of nowhere. I haven't seen or heard of anybody getting pulled over for loud pipes, lack of cats, or lack of muffler in over 5 years. And I think the last time I saw it, a state boy pulled over a guy on his way through town.

 

Wow, this could be a lot more of a headache than I realized. I will probably just leave it as it is.

California is such a BS state with all its dumb laws.

 

Cali laws are tough but it's federal law that put the cats there. Sure doing illeagal things can be a hassle.... thats the whole point! There are better exhaust options than stock and not all are illeagal ones. Of course in Cali you are more limited and they cost more. There are simple ways to override the downstream o2 sensor without ANY adverse conditions performance wise. Of course doing this without the use of the cat is illeagal.
Ive never heard of a trans going into limp mode over a dead cat but I'd be interested to know if thats happened. Standard trans doesnt even have a limp mode. Only the upstream o2 sensor is used to set fuel trim so if that sensor is working correctly you wont run rich. Commercial officers in the pickup trucks might be sharp enough to catch an illegal exhaust system , but your standard CHP wont much know let a lone care if you have the correct system or not. Course if you give any officer a reason to dig then anything is possible!

 

I know its federal law for cats to be installed, but CA have their stupid own deal. I was looking at magnaflow high flow cats, there were the ones available for the 49 other states and then CA legal ones in a whole separate category.
I also heard that if you do get checked for having no CAT, all you get is a fix it ticket. I know a bunch of people out here running a bolt on straight pipe on their diesels, when it comes time to smog, they just bolt back on the cat. That's what gave me the idea, but maybe its way different with the diesels.

 

California has its own additional laws on top of the Federal ones, and many local cops in CA are being taught to spot illegally modified vehicles because the citations for that are nice money makers.

And CA is deploying these smog sniffer trucks all over the place - funded by your tax dollars, to grab more of your money.:


They're even setting up checkpoints they call "mobile inspection stations" - participation is mandatory:
Smog Sniffer - YouTube

1. You heard wrong. If you have a dead catalytic, it's a fix-it ticket. If you have no cats, it's blatant (to them) tampering with emissions control equipment and a $2500 fine plus potentially all the other fun stuff like vehicle impoundment and jail time.

2. Diesels, especially older ones, are hard to smog in the first place so they can drive past the emissions checkpoints without raising a flag.

3. Taking your cat off and only putting it back for annual inspection looks great on paper. Not so great in reality, when every CA cop is looking to enhance his city's revenue by handing out $2500 citations.

 

Interesting... Id have to know more bout the SOCAL program before I comment, but here in the bay there is no such program. I can say with certainty, that this is were it would start if it were a state wide program. I dont see it catching on since emissions testing is not even required in many many counties here in Cali. As I said before, there are legal options available so you dont need to worry about the sniffing natzi's! DB codes are a whole different story.