Hey heres' a ??. I just had the exhaust done on my X and all was good until today, when I noticed I was down on power. It feels like maybe a knock sensor went or maybe the fuel filter is shot. It feels like I have a "dead spot" around 1500-3000 rpm range and the the S/C tries to kick in and it doesn't feel as strong as it should. It has 60000 miles on it and have never changed the plugs and/or the fuel filter. Help me out on this one!! Thanks