No cost air intake mod for 160sr

You may already be aware. Had a sports exhaust fitted, and a kandn filter fitted. Took off air intake scoop, and the first half of long intake arm. Left with air box, and half wide duct ending halfway in engine bay never got around to fitting a Megan scoop and new ducting. Makes a big difference. Doesn't look that good, but prefect results. Gets rid of the intake restriction after scoop. Air box and filter intact. Came across a picture of a 1.6 micra used in Canadian race series. Noticed that the cold air duct replacement they use ends at roughly same place as my remaining duct. A free mod that works well, and not too dissimilar to that used in the race series.
Exhaust and half intake removal made a noticeable difference. Like waking it up. Was advised a sports catalytic converter would improve it further, but didn't fancy cost. Anyone tried one?