our maxima has very little power till around 3000 rpm. it has been to mechanic (not nissan dealer) a few times. he puts some injectors in the "problem" cilinders. and then it seems okay but only for a short time. is there some stupid little sensor or something? what is he missing? is it in the plugs? is there a "special" spark plug they take that we are not using? idk what is in there now. i am simply frustrated w/this.

 

The 3rd gens are infamous for injectors. sometimes it's a good idea to replace all 6 at once seeing if you have the gxe you have to take the intake manifold off to get at them but it could be a number of things. Is the ses on? is there any codes? and as for spark plugs they seem to be happy with ngk platinums or if you wanted a step up ngk iridiums. I'd start by checking your spark plug wires if they are good and make sure the boots are down secure over your plugs and check the other ends at the distributor and check your harness connections on the maf and tps sensor. If all are secure it may be your tps, maf, distributor, or coil or if it's the se model coils. When was your last tune up? have you checked or changed minor things like your air filter?

 

all injectors have been changed (though not all at once.).it is the se model and coils changed though they seemed fine. tune up done at the same time as last injector change but it has been around 8 months ago. i do not know some of what you ask. what is the ses and codes? i would assume my mechanic checked the codes but how do i do it now? all wires seem tight and down. but tps and maf i do not know what they are.is the maf the thing i sprayed off that is in the intake? between 2 screens in a round tube?

 

The maf (mass air flow) sensor that would be what you sprayed between the two screens in your intake and the tps is (throttle position sensor) by ses (service engine soon) light i was just meaning is your check engine light on and if so were the codes checked with a scan tool? sounds like you covered a fair bit maybe try changing the tps or have your mechanic test it to see if maybe that's whats causing your issue. Was the issue there before you sprayed the maf?