Pre-CATS?
 

I just put on a set of Edelbrock Shorties on a 2002 Silverado 5.3 this weekend. I noticed a screen (almost like a MAF screen) in each of the y-pipes near the flange way before the CATS. This may be to straighten out the air before the O2 sensor? Whatever it is, it restricts flow. A TOG or ASM header (Mid-length) obviously cuts this piece out. Anyone know for sure what it is or ever tried removing it?

-thanks

Never seen them. My 01 didn't have them and I really doubt anything will be affected if removed.

My 04 didnt have them either.

Interesting....I could not believe it when I saw it. I may swing by the dealership to see if my mechanic friend knows about it.

-thanks

Hey rhayes5000......im from Oceanside. I was born and raised there. Let us know what you find out about that screen shit. Im interested in what that is.

Will do. You can see from the outside that the y-pipe is wider at the flange for about 6 inches where this screen is at then necks down for 12 inches or so before the CAT. It looks totally restrictive.

Oceanside is still quite nice, great weather and still not too crowded. Just good parts and bad parts of town like any city these days...

is it a flex fuwel model maybe.

Nope, the truck is not a flex-fuel.

The material in there is a pretty solid spiral-mesh. It looks real restrictive. I may take of the y-pipe this weekend to have another look and take some pics.