The 3.4L V6 engine runs lean with the TRD S/C, so larger injectors and another computer to control those injectors are needed. Once that's done you are resposible for engine management...no more trips to the dealer for drivability issues...they haven't been trained to deal with the additional computer. If the truck doesn't have this, the purchase, installation, and tuning will be expensive as you can imagine. Also, premium fuel will always be required for the S/C engine. Without the larger injectors we run the risk melting a piston and having to rebuild it. I ran the S/C without larger injectors and never melted it, but on some long climbs on mountain roads it was on my mind for sure <img src="/forums/images/graemlins/scared.gif" alt="" />