The emissions systems on the trucks is a pain to rig up for TRUE true-duals.
Most just put an h-pipe in place of the cat and run duals from there.
The factory y-pipe is the most restrictive place on these trucks, replacing it with an off-road y-pipe and a high flow cat is one of the best ways to get gains across the entire board.

 

got the headers in lat night, what a PITA for the drivers side, but the passenger side went in easy. ill have pics up in a couple of hours

 

so what all you end up doing ? you like the new power and sound ?

 

so thats why it was so friggin loud when you revved at me today...

 

1. The guy who did your work screwed you, you need a precat O2 sensor. The AFTER cat O2 sensor does not regulate the AFR. It is just to check that your emissions system is working.
NOW, there may be 2 reasons you are running lean:
1. You do not have the precat O2 sensor hooked up: Obviously you don't, so your computer (PCM) is doing what it does when there is no data coming from the precat to monitor AFR. It dumps max fuel. That is to prevent detonation in case your truck is running lean.
2. The guys at the shop hooked up the PRECAT O2, AFTER your cat. THat will tell the computer that you are running leaner than you actually are, thus you will get more fuel dumped in the CCs.

Check in and around your tranny for a) an O2 sensor wire with no O2 sensor hooked to it or b) a cut wire that used to have an O2 sensor.

The guys who did your work were idiots. You just have to find out if the Aftercat O2 sensor you have is ACTUALLY the aftercat.

 

Sorry guys, had some issues im takin care of. But below 2k power sucks but oncee i romp on it or climb past 2k it feels like i hit a shot of nitrous lol, i hope that ill gain some bottom end back when i get the new exhaust put on. And as for sound up till 2k or half throttle its actually quiter then my old set up, but if i drop the hammer it sounds like the gates of hell are opening. Wayyyyyyy to loud lmao

 

Good thing i didnt paint the headers before i put them in because the coating they came with burned off almost imediatly. And i just made a 300 mile drive and got about 13 miles to the gallon. Thats a 2mpg increase

 

have you had a look at your plenum? Mine was the same way before I fixed it... below about 2500-3000 RPM, nothing.... once you got to that magic number, it was like flippin' a switch. WOW.

 

Yea my plenums blown, buut in oct im gonna be puttin a new intake, so i havent fixed it yet

 

I want an m1 intake because i plan on getting new heads with the 2.02's around tax time, how much would it affect power with an m1 until i could get heads? Or would my old 360 breth just fine with a m1 and my headers?