Need help diagnosing

[mrpeepers]

Ok after a search on google and this site i still can't find symptoms that are similar other than it is "running weird"

Ok, I just replaced my O2 sensor and cleaned my KN filter. As for breathing mods the car has headers, fouled cats, and holy/rusty 2.25" exhuast with no muffler.

After installing the O2 sensor the car is running leaner for sure (less smelly) , but i noticed the car is making more power as per butt dyno, but there is small moments of "lagging" or bogging and the power is not linear. It is not a huge problem drivability wise, but when i feel a sudden surge of power in stop and go traffic it is annoying/scary at times(car is my DD). All this smooths out past 2500rpms. Should i disconnect/reconnect my battery to reset my ECU... this seems to fix stuff whenever i replace an old breathing part?

anyone experience this when restoring their s13?

[srpowered240sx]

fouled cat? does that means its clogged?? change that as soon as you can. and clean your maf sensor as well.