dbl_H thanks for the help. i looked at the website and i think that i'll give it a try. the  simulators are not that expensive so i'll try them out. my life is alittle crazy right now i have a kid on the way so it might be awhile until i get back to you'll on how they worked out.  and as for the other guy (5569) if you could read i know why the engine light is on i am just looking for away to keep it the way it sounds and to find out what other people know. and to hell with keeping anything stock dude. you are on the wrong page if you plan on keeping your ride stock.  

"but a few days ago the check engine light came on. i took it to a shop and they said it was because it has no cats."

right, i know that you know, i was actually just agreeing with you..

ride's not stock bro, I just live in CA and have to pass smog.  

hey i was wondering how can i get more horsepower and torque out of my '99 5.3ltr...i already have the k&n cold air intake, flowmasters, heddman header, and hypertech programmer...what else can i do other than getting a supercharger  

doubledeezy,

valvetrain, perhapse a different camshaft or longer ratio rockers. Convert over to LS1 electric fans. Taller gears in the rear end. Nitrous is fun. When you changed your headers and mufflers did you go to a bigger pipe? that could help. Some mild port & polish on the intake manifold & heads will help to. Larger bore throttle body, higher flow rate fuel injectors... higher flow fuel pump and an adjustable fuel pressure regulator.... all that should keep you busy  

This is in replay to the '00 with a vibration problem.  The extended cabs have problems with the drivelines being a little off center.  This is expecially a proble if the suspension is altered.  I loewered mine and had a huge vibration.  Belltech makes a relocation bracket that solved my problem.  It only took about 45 min. to install.  Hopefull this helps.  

there is so much out there for the LS engine. Air Flow Research offers as-cast and cnc-ported cylinder heads that with the right camshaft can add as much as 100hp.

FAST makes a bitchin composite intake manifold that is good for 15-25 hp.

Is a smog check a problem for you? if not then the sky is the limit even without a blower.