I have two questions concerning my 93 4.3 TBI. First, I was thinking of replacing my o2 sensor and fuel filter because my truck seems to run sluggish and bogged down. Could that help? My check engine soon light has been coming off and on for about 2 yrs. It seemed to happen after I got my Flowmaster and duels put on, and it usually only comes on after I have been driving for a while. What brand should I buy and should I put them in myself or pay someone to do it for me? Second, I have decided I want to add a little more juice to my truck, I was thinking of either JBA headers or a TB spacer (Air Raid, not a home-made one). What would be the best for the money? I know the headers are more expensive but is it worth the money or should I try the TB spacer since its cheaper? What would be a good price guess at a local shop for the intstall of headers and the spacer? Thanks for the info.