Originally Posted by '98200SXse

Well I know my mileage has went down here lately, since my Check engine light has been coming on / going off. I normally shift around 4-5K (5 speed), and I am hard on it sometimes w/ high speed full pedal to the metal, but I've been getting around 29 mpg, and it seems to be slowly dropping. I know my check engine light is on due to some of my emissions system not functioning correctly, Im also due for a tune up (77,000 miles). I also have 2.25 inch exhaust w/ magnaflow muffler so thats not helping, but when I first got the car I was getting nearly 38-40 mpg before I put on the exhaust/intake/ 17's rev wheels ; ( . Now I can't seem to get 30 mpg out of it, and my parents v-6 Buick century (4 door family car) gets more than I do !!