Strange raspy noise after fixing misfire issue

  1. My model of MX-5 is: MK 1 1.8
  2. I’m based near: Hampshire
  3. I’m looking for technical help or recommendations on: Strange resonating noise after replacing plugs and HT leads.

Hi All, looking for some mechanical advice regarding my MK 1 and a strange new noise its just developed.

I’ve recently replaced my spark plugs and HT leads to fix a misfire problem my MX5 was having and whilst that issue is now fixed, a new one has come along to take its place. After replacing the plugs and leads I it out for a quick spin to make sure all was OK and after just a couple minutes I noticed a very raspy noise under acceleration/high rev usage. Idling the car and coasting in neutral seems to stop the issue from occurring. Here’s a short video of it from a standstill MX 5 Noise - YouTube

My exhaust has been blowing for a while now so i’m hoping its related to that, but I have as much mechanical knowledge as a sack of potatoes so hoping someone with more experience is able to help me diagnose this issue.

Thanks all for any input and suggestions.