Ok so I have a 05 Sierra with a 5.3 and 2 1/4'' dual exhaust from the cats back with no mufflers. My question is can you cut out the cats and weld in pipe on this new of a truck? I've heard you couldn't do it after 1995 because it messed up your engine or something and your check engine light stays on.

 

need a pair of O2 simulators.
Call Caspers or ask which part numbers at summitracing.com

 

You are breaking federal law you know

So if caught, be prepared to pucker up and bend over for fed prison

 

Ya I know I will be but I live in the middle of bumfuck egypt. Closest town is 20 miles and it pop. is 246. Would these work? http://store.summitracing.com/defaul...=egnsearch.asp

 

Simulators or a custom tune will fix the SES light. You're losing lowend with the straight duals like that. I had the same setup you have now and lost some lowend. An x-pipe should help it out though. It'll help even out the flow.

 

I'm not really worried about performance since I have a 6inch lift and 36''s. Also how much mileage will be lost if I do this?

 

You can deifinitely weld in a pipe in place of the cats. The only problem you will encounter is that by not having the rear o2 sensors, your engine may run too rich or too lean....causing the engine to run a little rough and the SES light to remain on. The simulators should solve your problem though. I have them and have had no problems.

 

iirc it makes you a LITTLE rich not enough to worry about though. I have mine cut out and and noticed a increase in MPG and no loss in power. I do smell the exhaust a little more now though but I hate cats and wouldent put them back on