Good idea. I will check the post MAF to intake. In the meantime, I have been to the dealer. Coincidently it was an extremely humid day, right before a storm. Rode with the mechanic and the car did not ping. Couldnt even make it ping. But in talking with him, there was reluctance to do anything without a check engine light on. Claimed that everything is preset at the factory and can't be changed per EPA regulations. Does this sound reasonable? He did offer to hook up a "flight recorder" that I would activate when I detect a ping. Said it would detect things like the MAF, 02 or knock sensor, etc if they were flaky and not yet 'throwing a full code'. Waiting 4 weeks for dealer to call me with the 'recorder availability. Granted the ping might not affect the driveability of the car but, it takes away from the driving experience and I don't like it. Does the fact that it does not ping when the engine is cool and running rich, or when it is very humid outside give any hints? Thanks again