As posted elsewhere, you can recognize pinging as a loss of power at some RPM (some get it around 4000 RPM, there is a major incidence around 6500 RPM on other cars). The loss of power is sometimes subtle, sometimes drastic.

The loss of power is caused by the PCM protecting the engine from the pinging it detects using the knock sensor. Much better system than the 3rd gen RX-7 had! If you persist with WOT after hitting it, sometimes the PCM will "shut you down" to low power for 15 sec. and throw a MIL light.

Yesterday Maurice found a solution! He replaced the leading plugs on a local problem car with the new "8" heat range ones you can get from your local Mazda dealer. If you get blank stares from them, we can get them for you. Sorry, I don't know the P/N but just use the one on your current plugs, but replace the "7" with an "8". The hot plugs for winter use had a "6" in that place.

The leading plugs are the lower ones. Maurice also found they are easy to change from above IF you tie the hoses that are in the way to the large hose close to the firewall. Just use a ziptie and loop around them loosely (so as not to pinch them).

Those who live in areas that get winter will want to change them back to hot plugs when the season changes.

 

Useful info, thanks David. I have the problem with pinging at 6500 RPM, but as you know have resolved it for now with my own map. Sounds like I'll be getting a set of these "8" plugs down the road a piece.