Hey,
So i have had my 98 ex a little under a year now and slowly there are some strange things going on.

Whoever owned it before me didnt take care of it nearly as well as i do now. It had some worthless intake of some brand ive never seen and was starving my engine, it wouldnt even climb past 5kRPM without sounds like it might explode. So i swapped in a K&N. Much better, however a little while ago it started going into a very low idle. like 500 barely so it will kick back up to 800 sit for a sfew seconds and slowly fade back down. I scrubbed the crap out of my intake, still doing it. im debating removing it and doing a much thorough inspection. ideas?

Also, within a week of driving it my Check Engine light came on, supposedly my Catalyitic converter is no longer "optimal." any idea why it would just quit on me and should i replace it should i stick with OEM, and will other year cats fit in mine? personally id rather not spend 394$ on a cat from a honda store.