It very well could be the AFM, sorry, don't know how to test it, but my bud had a problem with his 3.0, replaced the afm and it went away.

Some guy with a 3.4 got pinging when he had alot of carbon buildup in the pistons/head.

Have you tried runnig 91, reseting the ECU and seeing if it still pings?
Maybe your ignition timing is advancing too far, causing the ping?

Good luck...

I posted the specs from the manual and posted what I got when I tested it. The format changed when the post actually showed up though-I don't know why. It's a little harder to read but all of the info is there.

I'm hoping Roger Brown chimes in... I don't want to buy another AFM if I don't need to.

As far as carbon build up, I can't imagine there is any. The motor only has 10,000 miles on it. At this point, it doesn't really matter much what gas I put in-it pings like crazy anyway.

Timing is spot on.

I opened up the AFM and started fooling around with the mixture. I'll drive it a bit tomorrow and see if it makes any difference.

Document your tweaks or you'll be pulling your hair out. <img src="/forums/images/graemlins/shame.gif" alt="" />

If you want to find an AFM, use www.car-part.com

After testing 6 or so used AFMs and 2 remanufactured AFMs, I finally found one that passed OEM specs with flying colors. I performed the lobotomy and things seem rather promising. It has only given me a slightly goofy idle one time and doesn't ping as badly as before. It still pings a bit-especially at partial throttle like when I give just a little extra to pass and in the heat of the day. I've put about 100 miles on it with 87 octane and it seems to be better.

I'd still like to check fuel pressure. That was something that was recommended to me along with the AFM by a Toyota wrench a little while back. I'm having a heck of a time finding a gauge though. As soon as I find one, I'll check things out. Maybe I'll find another problem and put an end to this once and for all!

I'll report new MPG findings at my next fill up. I'm hoping it's improved quite a bit.

Good, that's encouraging. Keep us updated.

Well, the first tank of gas (87 octane) returned 18.2 mpg with quite a bit less pinging. Not bad, not bad at all... That was an even mix of highway/city driving. The last tank of gas before the new AFM was 91 octane and returned 16.2 mpg.

The idle issue hasn't completely gone away but it's quite a bit better. I'm still trying to get my hands on a fuel pressure gauge.

Call around and see if you can rent one.

Fuel pressure is right on the money.

2nd tank of gas dropped to 16.xx-mostly city driving.

3rd tank is back up to 18.3-half highway and half windy mountain roads.

I guess I'm done. It still pings too much some times but I can't find anything wrong. I'll stick with 89 octane and plugs 1 step colder-that seems to be the best mix.

I'd love to have one more pull on the dyno just for grins but $ prohibits that.

Thanks for all of the help.