You dont need to buy expensive 02 sims for your truck. Look on the forums or just google manual 02 sims or spark plug spacers. You buy a total of 4 (2 per package), and drill out the one that get screwed onto the 02 sensor with a 1/2in. drill bit. After that you screw the other two remaining spacers onto the drilled out ones - then screw everything into your exhaust piping. So, everything will proceed as follows: Exhaust piping-regular spark plug spacer-drilled out spark plug spacer- then your 02 sensor. What this mod does is takes your downstream 02 out of the exhaust flow, therefore tricking your computer into thinking that there is a CAT between your first 02 and your downstream 02. That first spacer is only drilled out in order to fit it onto the 02 sensor. There is your fix... Spark plug spacers: $6 bucks, 02 sims: $100 bucks, Knowledge from the forums: Priceless...