Okay, I have searched all over this forum about this hesitation issue, and I only find on here info on the problem with the manual transmissions. I however have an auto 2k3, and it hesitates under load/hard acceleration. Let me explain, that I have not had this car for the past 8 months, and I'm sure that 87 octane gas has been used most often. Now I have this car back, I've changed plugs, cleaned maf, cleand throttle body, used fuel treatment and nothing but 93 octane or better. Would my hesitation issues be for something the same as the manual transmissions? Like a ecu reflash needed? Anyone else with an auto have this hesitation?

 

Could be a MAF going bad.

 

does it only hesitate under hard acceleration?

 

It could also be attributed to bad precats. They are notorious for failing and that could definatly lead to hesitations when you first accelerate.

 

I don't know if any of you have done this, but when you use the lower octane gas, it hesitates like that. Like at a full load, when passing on the highway and you floor it, it surges instead of a smooth power curve.

 

ECU reflash is only needed when you change something to the best of my knowledge... that 87 octane for the past 8 months could have messed up something in there. If not, then I'm gonna have to go with the official maxima.org diagnosis for 99% of all performance problems: MAF

 

there are three things

MAF
precats
drive by wire (electronical throttle)

all very common issues, you could try locating a new maf and see how that works, seeing as how that is the easiest and probably cheapest fix first.