Poping or Misfiring Under Hard Accelearation

[svt2205]

Thanks for taking a look.

Jack, I'm familiar with pinging, I had 2 4.6 modulars that were heavy pingers. That said, it could still be something like that, but it sounds different. I stand with my it sounds like something that's shifted in the bed and bumps into the tailgate, a sort of pop or light thud. Best I can offer for description.

Bill, it happened any time I stepped down hard on Friday afternoon and again Saturday morning. I had originally thought it might be due to the nice warm air we had (50's) but it was only 37 the following morning and it still did it.

I was running the canned level 2. It occured while accelerating, in gear. I did not notice anything during a shift. This only occured while under hard acceleration, say more then 50% pedal. I had been running on Level 2, since 3/15 and put over 1000 miles on without a hitch.

Returning to the stock tune seems to have things back to normal.

FWIW, I have AutoTap software. You know the package that allows you to read/clear codes and monitor, on a laptop, all sorts of different sensor output. If I knew what sensors to look at, I could set things up (probably not until next weekend) and see if I can see anything.

Thanks guys for taking the time to look into this. You're time/help is appreciated!!
Henry