Check Engine light & slight hesitation

It could be many different things based on your description. How long has it been since it had a tune-up? Do you have a check engine light on? Your coolant temperature sensor could be a likely culprit since it is what tells the computer if the engine is at operating temperature or not.

My Pathfinder was overheating until I realised the automatic transmission fluid was 3 qts. low. Filled it and Pathy runs at normal temp.

Is the check engine light on ?
Have you checked fuel pressure with a gauge ?

Hello
The engine and automatic transmission in this vehicles drive train are fully electronically controlled by a computer called the PCM (Power Train Control Module). Whenever a problem like this occurs the computer stores a record of the problem (there are of course some exceptions to this, like the fuel pump, engine coolant temperature sensor and MAF sensor for instance) in the form of a fault code in its memory, to read these fault codes you must have the systems memory scanned with a special tool. Once the fault code(s) are read you then must perform the appropriate diagnostic testing to find and resolve the problem(s) DO NOT REPLACE ANY PARTS UNTIL A TRAINED TECHNICAIN HAS DIAGNOSED THE PROBLEM TO AVOID SPENDING YOUR HARD EARNED MONEY ON PARTS THAT MAY NOT CORRECT THE PROBLEM

I suggest you use an OBDI code reader.

does it seem to sputter or hesitate when you excellerate through a turn?

DID YOU TRY THE THROTTLE POSTION SENOR

Have you had the engine scanned for trouble codes? You didn't say anything about a check engine light, but I think the computer may have some stored trouble codes that would have something to do with the problem.

Yes. Sounds like a plugged Trans filter or burned fluid. A full service on the Trans usually runs about $90 and is money well spent.

Another problem-which bugged me for 3 months, and had your similar symptoms, was a worn out fan clutch. It sent a shudder throughout the vehicle which mimicked a transmission issue. I know it sounds silly, but a new fan clutch cured my shifting issues.

The fan should rotate smoothly with some resistance (Engine OFF, of course) If you feel binding of any kinf, it probably is bad. Also check to see if you can cause movement fore and aft. If you can get it to rock back and forth, it is bad and needs to be replaced.

A fan clutch for that vehicle usually runs about $55

Could possiblty be an o2 sensor, or if it has the 3.8 engine in it make sure there isnt a crack in any of the coils.