I wanted to clarify the pinging that I am hearing.
It'* almost always when the TC is locked up.
I usually hear it at about 35 to 40 mph on a level spot. If I have been at that speed for a while and then lightly tap the gas, I will hear it. If I continue light pressure on the gas, the pinging will generally reduce in volume after maybe 2 to 3 seconds, almost like something tries to compensate. (O2 sensor ??????) I don't think the knock sensor has anything to do with that, it should compensate right away. When I finally get my scanner I will be able to tell if I am at full KR when I hear it.
I also hear pinging once in a while right when the TC locks up.
1992 green ssei. Tan leather, moonroof, power everything. 161k miles
Goodyear RSA Plus 225/60/16 VR on chromed factory crosslace rims. McGard chrome lugs.
Audio system: CD player w/equalizer, subwoofer (all stock).
Delco premium wires, NGK TR55 plugs, K&N stock style air filter. Ceramic brake pads. New rear brake tubing and proportioning valves. New wheel cylinders, front rotors and calipers. New front wheel bearings. Replaced crank sensor and harmonic balancer. Rebuilt instrument cluster. Cleaned A/C evaporator. Valve cover gaskets. Alternator. Front stabilizer links. Replaced all power steering lines and transmission lines. Cleaned MAF and IAC. New door appliques. Rebuilt steering gear. CERAMIC brake pads, I love them. I am listing all this in case someone needs advice on any of these repairs.