Ok. For some time now I have been battling this sputtering and crackling sound when I accelerate. It was accompanied by a p0171 lean code as well. I discovered something interesting last night. I put the car in neutral and revved it up. I could not produce the noise. The noise has always happened on acceleration and after 2nd gear. Any thoughts on this? Oh an p.s I had the transmission fluid changed about 2 weeks ago.

 

Sounds like pinging from a vaccuum leak.

Inspect all your vaccuum tubes, particularly the large one to the PCV.

 

i had a problem like this. it is annoying. i actually fixed it without knowing it. someone told me it was the catalytic conveter. and when i installed my new exhaust the noise dissappeared. my little brother was the one who pointed that out. lol. i asked my friend why this fixed and he said something about back pressure and i didnt unstand anything after that. lol hope this helps