My car just developed these problems within the last 3 days. The idle dips to 400rpms when the car comes to a complete stop but does not stall. Exhaust tone changed and a ticking sound is coming from the firewall directly in front of driver. Car lacks power untill 4000rpms. About three days ago I installed mils, cut my mac cai to rotate maf, and added fuel system cleaner with 93octane. I just rotated my maf back to normal and reset my computer again. Each time I drive my car the ticking sound seems to get louder. I think its an exhaust leak so i'll have that checked out tomorrow after school. Anyone else have some suggestions? My car just rolled 51,000 miles, does it need new plugs and wires or something else? I already changed my fuel filter. What else should I do? THANK YOU!!