Catalytic converter removal

[redroswell404]

My truck is a 5.9l 4x4 1500 slt. My buddy has a truck and he has no cat or muffler. I love the way it sounds but he said the straight pipe setup is very bad on your gas mileage. Will replacing the cat with a straight pipe cut my gas mileage in half like he says?

[neon_rt]

Removing the CAT is a federal offence, so I will not recommend doing so. You can replace it with a high flow CATCO performance converter for less $200.
Running straight pipes can potentially cause loss of power (as compared to a well designed low restriction exhaust). With straight pipes you are forcing the exhaust stroke to push all of the air that is in the system all the way out of the tail pipe. When the valve closes it causes the gasses to stop and start rushing back in, just in time for the next exhaust valve to open and be greeted by a high pressure wave. Not only does a muffler quiet the exhaust, it serves as a relief area for the exhaust pressure. CAT converters also tend to buffer the returning high pressure wave and so in most cases, having a high performance CAT will add some performance usually in the low RPM range and not cause high RPM power loss.

[redroswell404]

what about gas mileage does a straight pipe do to much damage to that?

[imtheoneandonlyD]

I dont have a cat on my 5.7. Milage didnt get any better/worse. I did however notice increased power after removing the cat.

[redroswell404]

where would i go to get that taken off

[redroswell404]

what about drilling a hole in the cat. converter