What computer controlled cars are you talking about I only build LS1/ls2/ls6 motors in my street/strip cars and they are comp controlled just because they computer is set one way from the factory does not mean it can never be changed And also cutting off the cat on your car is not WRONG like littering is WRONG not all areas require them and unless you drive your car at 50-60 mph from the time you start it till you park it then at some point your car puts out just as much pollution as if you didn't have one.

• First, the catalytic converter in your car is designed to be most effective at speeds of 50 to 60 miles per hour. Actions that reduce speeds below this level will lead to more pollution.
• Second, any engine must work more, consume more fuel, and emit more pollution when it accelerates than when it operates at steady speeds. Stop-and-go traffic thus leads to even more pollution.
• To make matters worse, catalytic converters are likely to cool off in stop-and-go traffic. When their temperatures fall below around 400 degrees, they are much less effective. Thus, in stop-and-go traffic you might as well not have pollution control equipment in your car.

And if you do not agree with me than fine but the EPA does
The catalytic converter, an invention that has sharply reduced smog from cars, has now become a significant and growing cause of global warming, according to the Environmental Protection Agency.
"The long-term problem is that even converting exhaust fumes into less toxic types - such as CO2...."
Apparently CO2 isn't the worst culprit:
But researchers have suspected for years that the converters sometimes rearrange the nitrogen-oxygen compounds to form nitrous oxide, known as laughing gas. And nitrous oxide is a potent greenhouse gas, more than 300 times more potent than carbon dioxide, the most common of the gases, that is warming the atmosphere, according to experts.Printed in the NEW YORK TIMES 2/09

 

it kinda funny how they force us to do things that a suppose to be better
and end up casing more and worse problems

like in Calif the mtb additive is a thousand times worse for the environment
that the emotions it reduces

 

That is why I never just do what ever the Government or News say is right. I always view both sides and make my own judgment on how to live and what is right and wrong.

 

Well I know for a fact that running it like that will not make it run better. While my buddy was doing the transfer drop on my xj somehow he broke my exhaust right were the head pipe meets the cat. That happened like 2 weeks ago so it's still not fixed. My jeep is loud as all hell and has a horrible spudder right off idle, when I'm wheeling the thing spits n spudders like crazy. Being in the motorcycle industry for years I know how backpressure affects motors.... not sure how much transfers to cars or trucks but I know with bikes having no backpressure makes for very bad bottom end power. Just like I'm having with my xj right now. I figure since I have to replace it I'm gonna do a whole system. I'll let ya know how it comes out

 

i cant seem to find a catback system for my 95 xj that would incress hp and make it sound bad ***

 

to different deals
are you sure you didn't damage the o2 sensor

I bet your just being lighter on the peddle because of the noise

 

i run a glasspack right after the cat and thats it i have it coming out the side of the jeep it sounds nice dont know about horsepower though

 

i live i California and it has to go out the back past the pasinger f***ing laws....

 

Na it's quite obvious when you look under the truck.... the whole head pipe is broke in half right before it hit's the cat. It was running great before that I just tuned it up.. plugs, wires, cap, rotor, fuel filter, air filter, belt, water pump, had one bad injector, think was running like a top. Now of idle when I punch the gas it spit's n spudders like crazy. I have to be light on the pedal cause the more gas I give it the more it spudders. I've been thinking twice when pulling out infront of people since this happened.

 

Yes back pressure does effect a motor in some way but when your running a full exhaust on a car with a muffler of some kind then back pressure isn't going to be an issue.

 

so back on topic.......

 

it has nothing to do with back pressure

 

we are on topic