The light came on shortly after I posted this question. I checked thoruoghly for leaks as suggested with carb cleaner while the engine was running. Also listened for vacuum leak noises. It ended up being the Mass Airflow Censor. Looking at the old one, one of the 2 wire (resister looking pieces) was black, the other silver. When I purchased the new part, both of the pieces of the sensor were silver.

The part was easy to replace and I purchased it on line. Locally the dealer wanted $199+$75 core deposit. The core deposit is refunded when you return the old core. I found it on-line for $154 (plus the same deposit deal). I had to mail back the old core, so the total was $160.

By the way, I noticed on the obdii web page that each of the manufactures has extra diagnostic codes. They have them listed. In addition, the reader which reads those was very expensive compared to the generic obdii reader.

No more pinging and the engine runs very well again!