Outer Limits 4x4 Board

HI all, got a bit of a question, When i turn on Air-C, idle seems that it drops down by a couple hundred rpm, Also on normal idle, wether air is on or not, the idles seem ok on the gauge, buyt sort of feels as if they arent right if that makes sense (like pinging). Ive got new Plugs, Leads and Fuel Filter etc, Any ideas to what it could be, ive asked mechanics for a tuneup, they tell me there not much that can be done Due to being efi.
Any Ideas/Tips that i can try, as ive also tried that Nulon fuel cleaner, didnt really stop it. Or is this normal. Thanks.
PS-Its 4cylinder, 1.6L EFI, 136,000 KM's, Automatic.

When u turn on the AC it dropping is normal.. it will probably also drop when u turn on the high beam, radio and other stuff.


Couldnt u also adjust the idle rpm to a good setting ?

ok np, thanks. I just thought it (idle) is meant to drop for a sec or 2, then go back up to normal. Will look into, thanks for the reply.