Maintaining a Skyline (how to?)

[kugas]

my car r34 gtt: The popping sound occurs when I have suddenly accelerated from a stop or especially after i switch on the aircond (high load).

I have never had a check engine light come after the event.

Is this a misfire? I changed my spark plugs 2 weeks ago and its recover for a while.

any suggestion/comment is appreciated.

 

[shark79]

sound from the engine ?exhaust? auto or manual trans?