I’ve had my 2013 Civic Si for about two months and the rpms started to bounce between 1k and 2k. I had a downpipe without a tune so I got it tuned and also took it several mechanics and they have no clue. We couldn’t find any vacuum leaks, we replaced he O2 sensor, we swapped out the throttle body for another oem one but to no avail. The idle relearn process also didn’t do the trick. Has anyone else had this problem?