What would cause my '02 Camry to hesitate, buck,

Most likely it's you fuel pressure valve located on the fuel rail. Just unplug it and it just has one t25 screws that holds it on.

My first guess would be a partially blocked fuel filter

ENGINE HESITATES WHILE ACCELERATION
LOSS OF ACCELERATION

It can be fuel pressure issue or it's the problem with accelerator pedal or its clogged filters causing there.
There are many other possibilities. I suggest you to go through the list of help links mentioned below, these will help you to confirm where the actual fault lies: -------
Jerks and Hesitates During Acceleration?
http://technoanswers.blogspot.in/2012/07/2004-dodge-town-country-jerks-and.html
-----------
Loss of acceleration?
http://technoanswers.blogspot.in/2012/02/loss-of-acceleration.html
---------
Headlights flickering and car hesitates to start?
http://howtobyme.blogspot.in/2012/02/headlights-flickering-and-car-hesitates.html
--------
How exactly the Vehicles Accelerator Cable works?
http://repairhelpcenter.blogspot.com/2011/11/how-exactly-vehicles-accelerator-cable.html
-------------
How exactly Vehicles Accelerator Pump Diaphragm Works?
http://repairhelpcenter.blogspot.com/2011/11/how-exactly-vehicles-accelerator-pump.html
--------
2000 Toyota Avalon: Engine Lean Codes and Knock Sound on Acceleration?
http://whatisbyme.blogspot.in/2012/05/2000-toyota-avalon-engine-lean-codes.html
---------
2004 Toyota Avensis: Acceleration And Deceleration makes noise on Front End?
http://whatisbyme.blogspot.in/2012/05/2004-toyota-avensis-acceleration-and.html
---------
Wheel hop under hard acceleration?
http://technoanswers.blogspot.in/2012/04/wheel-hop-under-hard-acceleration.html
--------
2009 Chevy impala accelerator pedal sensor?
http://technoanswers.blogspot.in/2012/02/2009-chevy-impala-accelerator-pedal.html
---------
Nissan Pathfinder stalls and bucks on Acceleration?
http://technoanswers.blogspot.in/2012/02/nissan-pathfinder-stalls-and-bucks-on.html
--------
Acceleration lag problem?
http://repairhelpcenter.blogspot.com/2012/01/acceleration-lag-problem.html
-------------
These details will help.
Thanks.

ENGINE HESITATES WHILE ACCELERATION

LOSS OF ACCELERATION

It can be fuel pressure issue or it's the problem with accelerator pedal or its clogged filters causing there.

There are many other possibilities. I suggest you to go through the list of help links mentioned below, these will help you to confirm where the actual fault lies: -------

Jerks and Hesitates During Acceleration?

http://technoanswers.blogspot.in/2012/07/2004-dodge-town-country-jerks-and.html

-----------

Loss of acceleration?

http://technoanswers.blogspot.in/2012/02/loss-of-acceleration.html

---------

Headlights flickering and car hesitates to start?

http://howtobyme.blogspot.in/2012/02/headlights-flickering-and-car-hesitates.html

--------

How exactly the Vehicles Accelerator Cable works?

http://repairhelpcenter.blogspot.com/2011/11/how-exactly-vehicles-accelerator-cable.html

-------------

How exactly Vehicles Accelerator Pump Diaphragm Works?

http://repairhelpcenter.blogspot.com/2011/11/how-exactly-vehicles-accelerator-pump.html

--------

2000 Toyota Avalon: Engine Lean Codes and Knock Sound on Acceleration?

http://whatisbyme.blogspot.in/2012/05/2000-toyota-avalon-engine-lean-codes.html

---------

2004 Toyota Avensis: Acceleration And Deceleration makes noise on Front End?

http://whatisbyme.blogspot.in/2012/05/2004-toyota-avensis-acceleration-and.html

---------

Wheel hop under hard acceleration?

http://technoanswers.blogspot.in/2012/04/wheel-hop-under-hard-acceleration.html

--------

2009 Chevy impala accelerator pedal sensor?

http://technoanswers.blogspot.in/2012/02/2009-chevy-impala-accelerator-pedal.html

---------

Nissan Pathfinder stalls and bucks on Acceleration?

http://technoanswers.blogspot.in/2012/02/nissan-pathfinder-stalls-and-bucks-on.html

--------

Acceleration lag problem?

http://repairhelpcenter.blogspot.com/2012/01/acceleration-lag-problem.html

-------------

These details will help.

Thanks.

try tuneup and fuel filter first would be my suggestion.

On some Camrys the radiator fan is run by hydraulic pressure from the power steering pump. I think the sensor you mention is the engine coolant temperature sensor, which is in the circuit which operates the fan when the engine becomes hot. If this fails the engine will overheat, yes. The fan does not cool the hydraulic fluid from the pump.

If your power steering fluid gets low the same thing can happen, but you would notice immediately as the steering would become intermittently harder.

ignition modules can cause problems like this also airflow meters and faulty fuel pumps

there are so many sensors nowdays that cause the same problem.---a bad throttle position sensor causes,:transmission shift issues,bucking, jerking, idle surging, engine cut off,hesitation on take off, surge while cruising down highway. a code will not allways set for a problem.

I'd say for you to replace the fuel filter. It should only cost $20. I'm about to do that right now because I'm having similar problems. I've had that problem on my previous car and it went away after I replaced the fuel filter.