While I am driving if I maintain a constant speed between 50 and 55 mph the truck will occasianally feel like it studders for a second then continues with a smooth ride for a few minutes then it happens again. At higher or lower speeds I do not feel this hesitation. no cel or trouble other than what I stated

Do you have an OBDII scanner to check the real temperature? Want to make sure it's not overheating. If it's normal, could be your temperature sensor starting to go out, or ignition switch. Any check engine lights? If so, get the code for me, can go from there. At a constant speed, you sure it wasn't a misfire instead? Check your trans fluid, make sure it's full. I was just in Tahoe, pretty sad not much snow at all.

Well, you did a really good job of describing the symptoms, but you didn't do so well describing the car. Are we talking about an automatic or standard transmission? are we talking about a four or six cylinder engine? You are asking about a drivetrain problem without giving any information about what drivetrain the vehicle is equipped with.

With all that said, IF we are talking about an automatic transmission being pushed by a V-6 engine, then there is a Technical Service Bulletin (TSB) that matches the symptoms you are describing. In this case, the problem is most likely being caused by a deformed or damaged exhaust pipe "A" mounting bracket.

Inspect the rubber bracket for cracks or torn rubber. If the bracket is damaged replace the bracket. Bend the stud on the exhaust pipe if necessary to get the stud to go through the bracket as straight as possible so the stud does not "ground" against the sides of the bracket. (see diagram)

check for problem drive line "U" joints or cv joints

Do you have a tow hitch on your truck? Does it rattle when driving on bumpy roads? I had a truck same year and make when on a certain road the timing would ****** problem traced to knock sensor.

loose belt

takes a long time to run the rediness test since there are 6 different tests to complete...

PROCEDURE 1
EVAPORATIVE EMISSION SYSTEM LEAK MONITOR
Inspection Conditions
Engine coolant temperature: 30°C (75°F) or less (The engine is stopped before the test drive is started).
Atmospheric temperature: 5 - 30°C (41 - 113°F).
Condition of A/T: Selector lever D range.
Fuel remained in fuel tank: 30 - 50% is recommended.
Time required: 16 minutes or less after started the engine.
Drive cycle pattern: One trip monitor (from start to ignition switch to "LOCK" (OFF) position. Well be completed while traveling with the following drive cycle pattern.
Test Procedure
Engine: start.
Accelerate until the vehicle speed is 89 km/h (55 mph) or more.
While keeping the accelerator pedal opening degree constant, keep the vehicle speed at 89 km/h (55 mph) or more and travel for 16 minutes.
Return the vehicle to the shop, then turn the ignition switch to "LOCK" (OFF) position.

PROCEDURE 2
FUEL TRIM MONITOR
Drive Cycle Pattern
Inspection Conditions
Engine coolant temperature: 100°C (212°F) or less.
Atmospheric temperature: -10 - 60°C (14 - 140°F).
Condition of A/T: Selector lever D range.
Time required: 30 minutes or more.
Drive cycle pattern: One trip monitor (from start to ignition switch to "LOCK" (OFF) position). Will be completed while traveling with the following drive cycle pattern.
Test Procedure
Engine: start.
Accelerate until the vehicle speed is 89 km/h (55 mph) or more.
While keeping the accelerator pedal opening degree constant, keep the vehicle speed at 89 km/h (55 mph) or more and travel for 30 minutes.
Return the vehicle to the shop, then turn the ignition switch to "LOCK" (OFF) position

PROCEDURE 3
CATALYTIC CONVERTER MONITOR
Drive Cycle Pattern
Inspection Conditions
Atmospheric temperature: -10°C (14°F) or more.
Condition of A/T: Selector lever D range.
Engine coolant temperature: Not set.
Time required: 16 minutes or more.
Drive cycle pattern: One trip monitor (from start to ignition switch to "LOCK" (OFF) position). Will be completed while traveling with the following drive cycle pattern.
Test Procedure
Engine: start.
Accelerate until the vehicle speed is 89 km/h (55 mph) or more.
Travel for 300 seconds or more while keeping the vehicle speed at 89 km/h (55 mph) or more.
Decelerate until the vehicle speed is within 80 km/h (50 mph) or less.
While traveling at 56 - 80 km/h (35 - 50 mph) for 10 minutes or more, fully close the throttle at least once in 2 minutes and decelerate for 10 seconds or more.
Do not repeat deceleration too often.
Vehicle speed may go below 56 km/h (35 mph) after the deceleration.
Stopping and braking are permitted. (If stopped or drive at 56 km/h (35 mph) or less for more than 5 minutes the monitoring may be stopped. In this case please restart monitoring from the beginning.)
After completing the above deceleration, bring the vehicle speed back to 56 - 80 km/h (35 - 50 mph) and keep it in the range until starting the deceleration again.
Repeat the above deceleration at least 5 times.
Return the vehicle to the shop, then turn the ignition switch to "LOCK" (OFF) position

PROCEDURE 4
HEATED OXYGEN SENSOR MONITOR
Drive Cycle Pattern
Inspection Conditions
Engine coolant temperature: 100°C (212°F) or more.
Atmospheric temperature: -10°C - 60°C (14 - 140°F) or more.
Condition of A/T: Selector lever D range.
Time required: 16 minutes or more.
Drive cycle pattern: One trip monitor (from start to ignition switch to "LOCK" (OFF) position). Will be completed while traveling with the following drive cycle pattern.
Test Procedure
Engine: start.
Accelerate until the vehicle speed is 56 - 80 km/h (35 - 50 mph).
While keeping the accelerator pedal opening degree constant, keep the vehicle speed at 56 - 80 km/h (35 - 50 mph) and travel for 16 minutes or more.
Stopping and braking during this operation are permitted. Keep the accelerator opening degree constant for 1 minute or more after each acceleration.
Return the vehicle to the shop, then turn the ignition switch to "LOCK" (OFF) position

PROCEDURE 5
EXHAUST GAS RECIRCULATION (EGR) SYSTEM MONITOR
Drive Cycle Pattern
Inspection Conditions
Engine coolant temperature: 100°C (212°F) or less.
Atmospheric temperature: 5 - 60°C (41 - 140°F).
A/C switch: OFF.
Condition of A/T: Selector lever D range.
Time required: 16 minutes or more.
Drive cycle pattern: One trip monitor (from start to ignition switch to "LOCK" (OFF) position). Will be completed while traveling with the following drive cycle pattern.
Test Procedure
Engine: start.
Accelerate until the vehicle speed is 56 - 80 km/h (35 - 50 mph).
While traveling 16 minutes or more at 56 - 80 km/h (35 - 50 mph) with engine speed 2,000 r/min or above, fully close the throttle at decelerate for 5 seconds or more until the engine speed reaches 1,000 r/min or under.
Do not repeat deceleration too often.
Stopping and braking are permitted (Rapid deceleration and sharp steering are not permitted).
After completing the deceleration, bring the vehicle speed back to 56 - 80 km/h (35 - 50 mph) and keep it in the range until starting the deceleration again.
Repeat the above deceleration at least 8 times by fully closing the throttle valve.
Return the vehicle to the shop, then turn the ignition switch to "LOCK" (OFF) position

PROCEDURE 6
OTHER MONITOR (Main Components, Sensors & Switches, Wire Breakage & Short Circuit)
Drive Cycle Pattern
Inspection Conditions
Engine coolant temperature:
100°C (212°F) or less (Except engine coolant temperature sensor monitoring).
30°C (86°F) or less (Engine coolant temperature sensor monitoring).
Atmospheric temperature:
5°C (41°F) or more (Except engine coolant temperature sensor monitoring).
-10°C (14°F) or less (Engine coolant temperature sensor monitoring).
Condition of A/T: Selector lever D range.
Time required: 21 minutes or more.
Drive cycle pattern: One trip monitor (from start to ignition switch to "LOCK" (OFF) position). Will be completed while traveling with the following drive cycle pattern.
Test Procedure
Engine: start
Accelerate until the vehicle speed is 56 km/h (35 mph) or more.
While keeping the accelerator pedal opening degree constant, keep the vehicle speed at 56 km/h (35 mph) or more and travel for 16 minutes or more.
Return the vehicle to the shop.
After stopping the vehicle, continue idling for 5 minutes, and then turn the ignition switch to the "LOCK" (OFF) position. Moreover, the vehicle should be set to the following conditions for idling.
A/C switch: OFF
Lights and all accessories: OFF
Transmission: Neutral

YOU HAVE A TORQUE CONVERTER LOCKUP ISSUE, HAVE SOMEONE LIKE THE DEALER,AUTO ZONE OR IF YOU ARE HANDY CHECK FOR CODES, NO CODES....THEN TAKE THE CAR OUT STEADY DRIVE AT AROUND 45 MPH, GENTLY HIT THE BRAKE PEDAL JUST ENOUGH TO MAKE THE REAR BRAKE LIGHTS GO ON BUT NOT HARD ENOUGH TO STOP THE CAR...DO YOU FEEL THE CONVERTER SHIFT IN AND OUT EACHJ TIME THE BRAKE PEDAL IS TOUCHED MAINTAINING A STEADY 45 MPH SPEED, IF IT THAT SAME SHUDDER YOU ARE FEELING THE TORQUE CONVERTER NEEDS TO BE REPLACED, NOT AN EASY JOB AS THE TRANSMISSION HAS TO BE REMOVED TO GET AT IT.SORRY ABOUT THE CAPS.......

You have to re-set the obd via using Nissan's approved drive-cycle which is;

1. Start the engine when the engine coolant

temperature gauge needle points to C. Allow

the engine to idle until the gauge needle

points between the C and H (normal operating

temperature).

2. Accelerate the vehicle to 55 MPH (88

km/h), then quickly release the accelerator

pedal completely and keep it released for at

least 6 seconds.

3. Quickly depress the accelerator pedal for a

moment, then drive the vehicle at a speed

of 53 to 60 MPH (86 to 96 km/h) for at least

5 minutes.

4. Stop the vehicle.

5. Accelerate the vehicle to 35 MPH (55 km/h)

and maintain the speed for 20 seconds.

6. Repeat steps 4 through 5 at least 3 times.

7. Accelerate the vehicle to 55 MPH (88 km/h)

and maintain the speed for at least 3 minutes.

8. Stop the vehicle and turn the engine off.

9. Repeat steps 1 through 8 at least one more

time.

If step 1 through 7 is interrupted, repeat the

preceding step. Any safe driving mode is acceptable

between steps. Do not stop the engine

until step 7 is completed. If you cannot or

do not want to perform the driving pattern, a
NISSAN dealer can conduct it for you.

I would check the throttle position sensor