ok check this out. my girl's maxima studder's when tha brake is applied at a full stop while the car is in gear. when it's in park or neutral it's fine. it sound's like the engine knock's like it's about to die. knock's then ok then knocks then ok. n keep's going. now do you think this is spark plug,problems(i just recently changed them last week). or is it fuel pump, filter. anybody have any ideas?

What brand plugs did you change them to, and try cleaning your throttle body.

at worst it may be a dying MAF sensor.

i used denso platinum plugs. and what's a MAF sensor. **** we just changed tha O2 sensors at tha dealership. and tha check engine light came back on again. anyways. im picking up my maxima. bought a 99 se-limited not stick tho. today so i should drop her's off n see what's wrong with it.

The maf sensor is part of the stock intake. From the airbox, follow the intake up, and you'll see the MAF (Mass Air Flow) sensor. it's a tube with a rectangle on top with a plug plugged into it.

Ther thing is tho, i killed my MAF, and it wouldn't idle at all. You would have to start the car up and throw it in drive and stomp on the gas to keep it going.