Hey there, I have a few burning questions I wanna run by you all... This is for a 99 tacoma, 3.4 auto with 169,000 miles on her.

1) Is there any way to turn off the "automatic door locks when truck is started" feature???
2) Has anyone else experienced the "buck" when you stop and then accelerate again? A spring guy told me it was because the back end sits low, so the driveline angle is off and tends to bind. He replaced 1 spring with a couple of others to give it a bit of help in the back. That fixed it for awhile, but now it's back. Anyone seen a solution for this?
3) I'm getting a bit of engine ping when accelerating. My MAF sensor is clean..I have a new air cleaner...my plugs are okay. What else should I check?

Thanks folks

1) dunno
2) It's your tranny kicking down to 1st after you stop. Programmed to do so for several reasons. A new, stiffer or anti-wrap-leaf equipped spring pack may reduce the thump a bit, but not for the reasons he suggested and it's a pricey solution to a minor annoyance (unless you wanted more wheeling ability too).
3) Try changing gas brands. Also, have you run BG44K through your system regularly? Try that, you may have some carbon buildup. My 5VZ-FE loves just about any cheap regular I put in it, but mine is out of a '96 and has seen BG44K regularly.

My 04 has a bit of a thump when taking off on occasion, but that is because the tranny is still in 2nd gear (after coming to a stop). When I start off it shifts quickly back to 1st. Only happens every now and then, or I don't notice it that often. May be the same thing you are experiencing...

Sometimes I'll be sitting at a red light and the tranny will kick back to 1st and kinda lurch my truck forward a tad...

I don't think it's your tranny bud... I thought mine was too, until I heard about this driveline thump. It's a known problem with tacomas. The toyota dealer even has a TSB about it that says to remove and lubricate the slip yoke.

As for the engine ping; what's BG44K?

BG44K is an additive that is typically used for cleaning up carbon buildup. Good parts stores carry it.