ok when i drive my car and warm it up a bit, it starts hesitating upon acceleration, and even when its idling...then sometimes when i hit hard on the gas, it makes this loud "spitting" noise as it hesitates, and i can hear it even more now that ive put a cai, cat back, and hi flow cat...i would reset the computer and check the codes but i cant because im an idiot!! i was resetting my computer and that little screw thing that you have to turn snapped off because i pushed to hard! mother fuc*er!!!!! ....somebody help!!...ive pumped this thing with fuel injector cleaner like 6 times and i only use premium fuel...does anyone have any idea what this god awful noise/hesitation is??????????????????

 

Assuming from your name, you have a 99 Max. 99s have a coil pack problem so it's probably one of the coil packs dying...

 

what is a coil pack? how much does a new one cost? can i replace it myself??

 

Since you're new, read the stickies at the top (lots of helpful info) before you start getting flamed

Look at the "how to replace spark plugs" link in the How To thread stickied at the top of the forum for instructions. New one is about $60/each and you can buy it from (search for "ignition coil" and get the Mitsu ones):
http://www.jerryromenissan.com use promo code "maxima" after you add it to your cart
http://www.partznet.com free shipping

Unless you want to replace all 6 (you can find a used set on eBay), you'll have to narrow your problem down to the bad coil pack. With the car running, unplug them one by one and see which one makes little to no change in RPMs (since the car is running like crap with a bad coil pack, unplugging the bad one won't make much of a difference)

Until you get the bad one replaced, don't drive hard

 

Prolly coil packs as everyone has mentioned...atleast that was your original problem. Really sorry to say that you've messed up ur ECU.

That screw needs to be turned counter-clockwise to it's stop position, to allow proper functioniong of your car. So take apart ECU and JB weld that screw, and you still have the fix that "spitting" problem (coil packs prolly).

I bet you could just start replacing coil packs....and fix the problem...but how do you expect to self-diagnose CEL's now? Maybe ur lucky enough to rely on OBD scanners from now on...and hope ur screw is on the correct "rest" position.

 

i also had this problem but it was my MAf, check ur codes if u can maybe goto autozone and let them check the codes