Spark plug OEM BMW or OEM Honda

Guy was gunna charge me $720 USD for changing my serp belt and another $550 USD for changing just my spark plugs. That's $20 for the serpantine/drive belt, $150 for the belt tensioner and I think another like $120ish for spark plugs (B58 engine). So in total I saved myself roughly $1,000 just doing it myself.

Yes, a bad spark plug, incorrect type of spark plug, or a wide spark plug gap can cause a coil to fail. If electrical resistance in the secondary ignition circuit is too high the coil must generate a higher voltage to fire the plug.

Only issue I’ve had is having 2 spark plugs blow out. The first time required a replacement head and the second was fixed with a helicoil. Most reliable vehicle I have owned.

I have an aero 50. I don’t recall what’s recommended on it, but when I was living in the Pacific Northwest, I found that while using premium, it ran significantly better. Smoother idle, better acceleration.

I remember the first time I did anything besides oil, it was spark plugs and power steering fluid on my old accord. Starting it up after had me nervous, second guessing everything I did.

I did track it extensively, probably 3-4,000 km of track use. The only thing it needs is brake fluid and better pads and you're good to go. My car was flawless for the entire time I had it. It threw a CEL right before I sold it that was solved with a simple spark plug change. It never overheated at the track and it was a lot of fun there and very refined and comfortable for highway travel.

And timing belt, and spark plug change every 90 K miles or so.

Sounds like it could be a spark plug. For some reason the Prelude likes to eat through them. Shows the exact same symptoms you describe (loss of power, different exhaust note).