[Help, Motor in SSS seems to be running flat]

thanks guys im gonna givem a shot

[Help, Motor in SSS seems to be running flat]

All of the sudden my truck just runs like poo. I mean its not horrible but its deafinatley a noticable powerloss and down to like 9 MPG from a 15 average. the only mods i have are KN 77series intake and a custom exhaust with a 50 series flowmaster. I've never had any problems before, i checked my air filter and its really not that dirty, but im gonna clean it anyway to be safe, you guys got any ideas on things i can check

[Just put a new exhaust on my 4wheeler]

me and my dad built a blaster , tons of modsvand you know it just wasnt enough, we always rode bikes the thing was just damn slow, so we put a rebuilt yz490 egine it now it moves