Hey mazda enthusiasts. I need your expertise.

My car is a 2002 mazda protege5 2.0l 4cyl

what ive done to it:
"new" used motor with 15k miles on it.
Brand new transmission w/ 3 yr warr.
Removed precat and istalled header(had to extend egr tube)
custom cold air intake with spectre filter
brand new plugs and wires
lowered 3" with spring
stereo and other cosmetics

now the real question..... Should i get the car tuned? The car seems to be idling low at about 750 rpms. Also surges or sputters at idle and light acceleration. I was gettimg a p0303 code which was misfire cylinder 3, so i just replaced the coil packs. With the performace header and intake, do you think i need to get the car tuned as it may be throwing off the computer without the cat. Many have said clean the egr, but ive done that 3 times already. Desperate to get this beauty running correctly. If i do need to get it tuned, where in the atlanta area can i do that? Thanks in advance.

 

**update** cleaned my maf sesnor and all seems to be better. But still, should i get it tuned?

 

What do you think tuning would do for your engine?