In the search for more horsepower I installed Mid America's off road exhaust which eliminates the pre-cats and converter. I finished it off with a set of Flowmasters. Since this point I have lost alot of low end torque. Argueably the car is slower than when I started. I increased fuel pressure to help offset the apparent lean conditions. It helped only marginally. It was recommended that a universal three wire heated oxygen sensor be used due to the lack of heat without the converter. Any suggestions on the validity of this statement. I have installed a prom chip from SLP, under-drive pulleys, and have removed the air pump. It still GTECH's low to mid 14s (at 5200 ft elevation). Running without the exhaust netted similar results. I am open to suggestions. There do not appear to be knowledgeable Tuned Port mechanics in this part of the world.