I just bought my first 4runner .I have always wanted one and the second gen body style always looked good to me .I got a 1994 with 147,00 miles .I paid 3400 for it and it is rust free and really clean with nothing major wrong with it .I was wondering if i put any cold air intake or performance chip or exhaust will it hurt or help the gas milage .I most want to put an exhaust system on it .But if any of these items will hurt the gas milage i will probaly leave it alone .If the chip is ok to put in what brand do i need and where do i get it .I saw some on ebay for really cheap claiming 20 hp .Are these any good ? Thanks for any and all input .