Ruben525 Posted October 13, 2009 Report Share Posted October 13, 2009 Ok I have an extra set of cats piping and all cats are no good I'm thinking of gutting those cats and putting them on my truck but not sure if it's worth it. So I hear good and bad things about doing that I hear the you get more power and better mpg is that true?(I like how it sounds mean too I have a one chamber flowmaster that dumps down under my truck) On the other hand i heard it's not good for your truck. So is it worth it what are the ups and downs? Quote Link to comment Share on other sites More sharing options...
misterp Posted October 13, 2009 Report Share Posted October 13, 2009 The FIRST thing I did on my truck was gut those SOBs. The bad: as you are in CA your truck will not pass smog without functioning cats, it won't pass the sniffer. You can disable the converter error codes etc so the SES light will not come on, and you will pass the visual inspection, but the sniffer will still get you. The good: IF you have your PCM tuned correctly, then yes you can improve mileage ABOVE 74-mph because the programmer can turn off catalytic converter overtemp protection; you might notice that your freeway mileage plummets like a rock above a certain freeway speed (75-mph) it's because at that speed the PCM dumps in more fuel to cool off the converters. The only valid reason to eliminate cats is if you are running gasoline 95-octane or higher, gasoline with lead or a lot of additives (race gas), or must run very rich AFR's with nitrous or forced induction - these conditions will foul cats, and they must be removed. If you remove/gut cats just be prepared to put them back on for CA smog tailpipe/sniffer inspection. Mr. P. Quote Link to comment Share on other sites More sharing options...
SSplaytoy Posted October 13, 2009 Report Share Posted October 13, 2009 Gotta agree. When I had the radix I went through the stock cats and hi-flos. But since your in Cali your kinda screwed. Although I do remember a member a long time ago with the smog issue. He welded flanges to each side of the cats and could take them out and replace them with pipes whenever he wanted. Try a search for it. Quote Link to comment Share on other sites More sharing options...
Jaymz Posted October 13, 2009 Report Share Posted October 13, 2009 The FIRST thing I did on my truck was gut those SOBs. Mr. P. Quote Link to comment Share on other sites More sharing options...
Fireman31 Posted October 13, 2009 Report Share Posted October 13, 2009 Gut 'em, your exhaust will smell soooooo much better. Quote Link to comment Share on other sites More sharing options...
Ruben525 Posted October 13, 2009 Author Report Share Posted October 13, 2009 Yea the smog thing sucks but I have an extra set of cats so when smog come back around in about a year and a half I'll have to swap them out but I'm just not sure if it's even worth spending the time to do all that Quote Link to comment Share on other sites More sharing options...
misterp Posted October 13, 2009 Report Share Posted October 13, 2009 Yea the smog thing sucks but I have an extra set of cats so when smog come back around in about a year and a half I'll have to swap them out but I'm just not sure if it's even worth spending the time to do all that On a supercharged truck running mid-12's, removing the cats will gain you about a tenth in the 1/4-mile; there is not a lot of performance to be gained but sure it helps a little. The best thing about gutting the cats is that when you combine with a good catback with the stock manifolds it sounds awesome, I installed a Corsa Touring and with gutted cats and a 2800-rpm converter I regularly had people compliment me on the sound of the truck. After installing a set of cheap longtubes it sounded like crap and I hated it, but with the ARH headers it sounds great again at WOT but not quite as good tooling around town as with the stock manifolds IMO. If you really want to go fast though they eventually will have to go, because fouled/plugged cats will kill an engine, it's happened on the forum here a few times. Mr. P. Quote Link to comment Share on other sites More sharing options...
angels05ss Posted October 13, 2009 Report Share Posted October 13, 2009 On a supercharged truck running mid-12's, removing the cats will gain you about a tenth in the 1/4-mile; there is not a lot of performance to be gained but sure it helps a little. The best thing about gutting the cats is that when you combine with a good catback with the stock manifolds it sounds awesome, I installed a Corsa Touring and with gutted cats and a 2800-rpm converter I regularly had people compliment me on the sound of the truck. After installing a set of cheap longtubes it sounded like crap and I hated it, but with the ARH headers it sounds great again at WOT but not quite as good tooling around town as with the stock manifolds IMO. If you really want to go fast though they eventually will have to go, because fouled/plugged cats will kill an engine, it's happened on the forum here a few times. Mr. P. by any chance do you have a sound clip of your truck,i have the cats off on my truck but havent had time to gut them out Quote Link to comment Share on other sites More sharing options...
mcmahan Posted October 13, 2009 Report Share Posted October 13, 2009 i deleted mine i love the sound Quote Link to comment Share on other sites More sharing options...
misterp Posted October 13, 2009 Report Share Posted October 13, 2009 by any chance do you have a sound clip of your truck,i have the cats off on my truck but havent had time to gut them out No I don't, and the truck is not running at the moment; but when it is again, I'll make sure to get it on video. Mr. P. Quote Link to comment Share on other sites More sharing options...
SSplaytoy Posted October 13, 2009 Report Share Posted October 13, 2009 I love the sound, but put in an x-pipe. It was a bit too loud inside the cab sometimes. Quote Link to comment Share on other sites More sharing options...
SSplaytoy Posted October 13, 2009 Report Share Posted October 13, 2009 Because I'm a nice guy .........here ya go....chiel's setup Just if you do this, keep some gaskets handy. Quote Link to comment Share on other sites More sharing options...
angels05ss Posted October 13, 2009 Report Share Posted October 13, 2009 Because I'm a nice guy .........here ya go....chiel's setup Just if you do this, keep some gaskets handy. sweet set-up,i think my ARH lts are gonna be a bit more difficult to do. Quote Link to comment Share on other sites More sharing options...
angels05ss Posted October 13, 2009 Report Share Posted October 13, 2009 anyone with a catless/gutted cat system have a sound clip (corsa??) Quote Link to comment Share on other sites More sharing options...
Fireman31 Posted October 13, 2009 Report Share Posted October 13, 2009 anyone with a catless/gutted cat system have a sound clip (corsa??) http://www.silveradoss.com/forums/index.ph...356&hl=GMPP Quote Link to comment Share on other sites More sharing options...
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