Spark plug Denso or OEM Mazda

I was running APR coils and went back to OEM. That helped. So did going to the Denso 5750 plug and getting an EQT grounding kit.

So I decided to I replaced my spark plugs. There was a ton of carbon build up in the first cylinder, and oil on the 2nd, 3rd and 4th spark cylinders, including the spark plugs. It’s running way smoother now but there is still some jerking but it’s not as violent as before.

The DENSO spark plugs are 6 for $23 at walmart. These get great fuel economy , smooth idle, Great Power.

Have some I'm waiting to try out in my turbo 4age after using bkr7e ngks for years. I mean denso is an A1 company and they offer heat ranges colder than NGK so probably worthwhile for my turbo engine.

2019 4 gen - dealer sparkplugs were part number ZC20HPR11 > Denso spark plug.

I’m from EU, Scandinavia and that part number were on my original ones I pulled out.

Plugs(Denso IK22) coils(DENSO or Hitachi) and a valve adjustment, all due at 100k. They really do make them run better and much more reliably.

I installed Denso a few weeks ago.

Densos. Buy them off rock auto.

I bought the plugs from Toyota (Denso). I asked for the old plugs off. The plugs I got back were NGKs that were installed at the factory. I can’t say I notice a difference really (except new plugs did seem to make a difference).

the densos work fine, the point of swapping is not for any performance gain, rather to prevent shattered ceramic from raining into your cylinders