Spark plug OEM Toyota or AC DELCO

My feels like it’s running brand new with 100k plus miles ????

Use the AC Delco iridium original plugs. Many sites will only show the double platinum as a replacement but every time I've ever driven an engine with those in it, it pinged or idled rough and iridiums always fixed it.

Over the years I’ve found that the factory recommended spark plugs typically work best. There are exceptions, but my ‘95 5.7 recently got some plain Jane ACDelco plugs and it is running great.

I just put in regular AC Delco plugs and it runs great.

I bought six OEM spark plugs at the Toyota dealership parts counter and it was $12!

Fresh AC Delco copper core plugs are all you need. Start with the stock replacements and go from there.

The new plug is AC Delco 41-156. Cannot tell any difference in my Gen 2 after replacing plugs. It ran fine before and did afterwards as well.

Last thing on my agenda is the spark plugs. Got it with 131K and I’m pretty sure the previous owner literally sold it to avoid doing them. I know I should have done them yesterday, but god it looks like a bitch, even with Car Care Nut’s guide. I’m planning on doing the job with the new plenum gaskets, and ignition coils while I’m back there.

I bought eight new AC/Delco from eBay. While gapping the plugs, I noticed that in two of them, the ceramic was not concentric with the body of the plug. It's difficult to measure, but it's easy to see by eye. I'd estimate the error is about 0.02 to 0.03 inches.

I had the same experience and ended up getting a code. Swapped them out back to AC Delco and never had an issue.