Has anyone gutted their cats on an LS1 truck? I considered doing it on my f-bod... Im concerned with issues on the OBD sensor. Guess the EGR mod would take care of that.

Thanks!

 

don't bother....the cats will outflow the motor most of the time unless you are running forced induction, and the loss in backpressure will affect your low-end torque negatively

 

Not sure about the trucks but on the F-bod I gained 4mph in the 1/4 and on my Vette I changed the exhaust to a Z06 Ti and took out the cats and went from 106.5mph to 110 avg. Evem dynoing between no cats and hi-flow cats you gain about 5hp so going form stock cats to no cats is definately worth power.

Again, this is tried and true on cars, not sure baout the truck yet but I will be trying it when I install my new headers

 

There is not much to gut. You can see right through them. The best thing to do is weld in a set of flanges and build spools for them. Then run 02 sims. I don't guess you have to worry about emmissions testing up there huh?

 

I took a 2" pipe and a sledge hammer. Took about an hour, there is alot of honey comb material in there. Once you get it out take a wire brush on a drill and clean up the inner walls. when your all said and done vacuum it out.
I didn't see any gains at the track but sounds alot cooler.
Emissions? what's that?

 

creederado, i'm planning on gutting my cats too, was wondering if it makes it a good bit more louder. let me know if you can. thanks

 

i heard that gutting your cats is almost pointless. if you just gut the cat and weld it back on then the exhaust flow is going to have a lot of turbulence. just think about it.air is going from say a 3" circular tube into a ~4" oval tube and then back to a 3". its best just to weld in a cutout or a single pipe in its place.

 

I did think about it, and when you don't have a shop in a 150 mile radius willing to replace your cats with strait pipe than your left with the alternative. With the az headers all I had to do was unbolt the y-pipe bash out the cat and bolt it back in, no welding.
I tried doing the strait pipe trick before, my self but it is hard when you can't weld exhaust tubing. Also when I had my stock y-pipe and unbolted my catback from the flange. it only gained 5 hp above 5000 rpm on a dyno, so I'm not going with cut outs and opted for the quicker easier route. I really don't think the turbulance caused from a 7"-8" gutted cat makes any differance but maybe someday when I invest in a mig welder I will redo the right way.
as far as sound I think it gave the truck a deeper tone, also lounder.