I replaced the fuel filter a few months ago (Wix) and plugs(Bosch Platinum +4) last year (they always look good)...cap and rotor are probably about due. The thing is,it runs really well,like always.

I've heard that cats get restrictive over time and that the O2 sensor can get "tired". Thw decrease has been in hot and cold weather.

I have the factory maintenance manuals;haven't really t/s it yet.