RPM fluctating after muffler delete
I have a 2018 Civic hatchback sport that I recently did a muffler and resonator delete on. Love the sound but I noticed that when accelerating or deaccelerating I get RPM fluctuations and they can be often sometimes extremely dramatic as far as 400 rpm differencing. Its stable during idle. Why is this happening? I've been reading a lot how others didn't have issues with doing this - does my car need to be tuned? From what I've read on various sites is I don't need back pressure, so what's the deal? Thanks for any help.