Rough idle/stutter MPS Gen2

So over the last week I’ve noticed my MPS running a bit differently. At first i thought it may have been some bad fuel. Today i started the mazda and noticed it being more rough on idle/cold start. After reversing out my driveway it did a solid backfire (not just the normal sputter/mps tone).
Also last week when driving in 2nd/3rd i have noticed a very slight stutter around mid throttle, very subtle but easy to notice when driven daily.
any ideas on what this could be? MAF sensor?
any help would be great cheers

edit: car is stock with resonator delete

Some cold start miss/pop isn't that unusual in BK, I can only think of once I got a solid backfire from mine (BK) and that was in stop start traffic. I'd suggest getting an OBD log onto it, possibly could be bad fuel - have had that once with my BL. I'd be eyeing knock retard values, fuel pressure, manifold pressure, long and short term fuel trims and AFR. That's where I'd start. Some other members might have some good suggestions for what should be logged in this case.

If bad fuel i.e. had toluene in it or something can take a few tanks to be completely rid of it - that's what I found anyway.

Spark plugs pop to mind as something that might need checking. A _careful_ clean of the MAF wouldn't go astray...