I havea question about installing an electric cutout on our 2003 Yukon. Is it worth it to purchase the o2 simms and place the cutout before the cats or should I just put it in the intermediate pipe?

I haven't checked very thoroughly under the truck to look for placement ideas but if anyone has any good suggestions from having done this before please chime in, thanks!!

 

I run one 3" cutout just behind the wye-pipe.

 

Is this on a 5.3? Got any pics?

 

i kind of like the idea of "in place of the cats"

 

If you're installing the cutout plate for performance purposes, install it before the cat. If you're installing it just for the rumble, put it after the cat. IMHO a muffler by itself doesn't sap enough power to justify paying for a cutout pipe and plate. I have a high-flow aftermarket cat and cat-back exhaust so I don't notice much of a difference power-wise when I have it flipped open, but the look on the ricer's faces when their fart cans get drowned out by the sound of an open-exhaust V8 is priceless.

 

This would require O2 simms right? Just trying to figure if the extra cost is worth it, the truck is new and I don't want to cause any 'SES' light crap...

 

If you have an O2 sensor immediately before/after the cat, placing the cutout pipe before the cat may trip a computer code while in operation depending on how sensitive your computer is (I'm sure someone with more Silverado knowledge will jump in at some point). I know a number of people are using these plates on their Dakota R/T's and haven't tripped a code yet, but for the most part they're only opening them for short bursts at a time at the track then keeping them closed while on the street.

I keep my cutout plate open relatively often, but I use O2 SIMMs because I removed the restrictive pre-cats that came with my truck.

 

Mine is after my high flow cats/y pipe just before the Magnaflow muffler. My exhaust seems to have just barely enough back pressure even with the cutout closed, and when its open its a total DOG - no low or mid range power at all - its just very loud. Now I haven't tried it open with the 50 shot yet, maybe I'd benefit power wise from it then...

 

What do the chassis dyno results show with these installed?

 

Anyone?