M
modelbuilder
Guest
Just wondering?
BKCowGod
Automotive ADHD is fun!
In California, you won't pass a visual and in most cars will fail the sniffer on a smog test. You will also pollute, in exchange for negligible gains in performance vs. having a new, functioning cat. In the olden days, cats were a lot more restrictive, but these days you can toss a free flowing modern cat into a car and it will be so close to not having one that it's not worth the trouble.
That said, the engine will also be angry with you unless you deal with oxygen sensors and the like - modern computer controlled engines expect that cat to be there and get upset if it ain't!
Why you ask?
That said, the engine will also be angry with you unless you deal with oxygen sensors and the like - modern computer controlled engines expect that cat to be there and get upset if it ain't!
Why you ask?
M
modelbuilder
Guest
I figured something like that would happen.
I asked because I just wondered what would happen.
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Mighty Dodge Ram
Explorer
Does your cat sound like it has loose gravel inside when you rev the engine? Or are you just thinking it might add some ooomph? I've had 3 in my Dodge...the 5.9L eats them every 80k or so. Agreed with everyone else...no gain and possible pain. :sombrero:
Don't cross the streams...Ghostbusters?
R_Lefebvre
Expedition Leader
How about this one:
Your truck will stink. Most people forget what un-catalyzed cars smell like. They friggen stink. People behind you will smell it. You'll smell it when you're outside the car. And you'll smell it off-road if you have a tail wind.
I found it objectionable on my trackday car, so I put a high flow cat on. I also passed emissions, though it was close.
Your truck will stink. Most people forget what un-catalyzed cars smell like. They friggen stink. People behind you will smell it. You'll smell it when you're outside the car. And you'll smell it off-road if you have a tail wind.
I found it objectionable on my trackday car, so I put a high flow cat on. I also passed emissions, though it was close.
truck mechanic
Adventurer
Yep, another vote for leaving it on. If you have a newer truck with o2 sensors infront and behind the cat you will set a check engine light. That could even happen with a high flow cat so becarfull what you do under there.
Paul
Paul
Larry
Bigassgas Explorer
The cats are part of the Federal Emissions requirements. If you remove it, you are breaking Federal Law and that isn’t good. Ripping the tag off your bed mattress is also against the law.
On the other hand, I don’t believe in the back pressure story. I am running a 2002 Vortec in a 70’s truck without cats with no issues. In fact, this truck has much more low end torque and high end HP than a stock Silverado I have with the same engine. The transplanted engine has had the PCM tweaked to toggle off the downstream O2’s, EGR, and a few other nonessential things. Not saying that removing the cats will yield great gains, I just don't see their absense being an issue outside of breaking the law. Custom tuning of the PCM is where power can be gained.
On the other hand, I don’t believe in the back pressure story. I am running a 2002 Vortec in a 70’s truck without cats with no issues. In fact, this truck has much more low end torque and high end HP than a stock Silverado I have with the same engine. The transplanted engine has had the PCM tweaked to toggle off the downstream O2’s, EGR, and a few other nonessential things. Not saying that removing the cats will yield great gains, I just don't see their absense being an issue outside of breaking the law. Custom tuning of the PCM is where power can be gained.
R_Lefebvre
Expedition Leader
Oh right, the backpressure thing. It's bunk. At worst, you will move the existing torque peak up in the rev range a little bit, but ultimately, the value will remain the same. More commonly, the low-down torque value will remain the same, but you'll gain more higher up in the range which makes people *think* they lost torque down low.
Ruffin' It
Explorer
Don't forget the $2,500 fine
