2002 Chevy Malibu 2002 malibu hesitation on acceleration

Possible Causes of Engine Hesitation

Dirty fuel injectors (cleaning the injectors often fixes this).
Bad MAP (manifold absolute pressure) sensor
Bad TPS (throttle position) sensor
Bad or dirty MAF (mass airflow) sensor
Low fuel pressure (leaky fuel pressure regulator or weak fuel pump)
Vacuum leaks (intake manifold, vacuum hoses, throttle body, EGR valve)
Bad gasoline (fuel contaminated with water or too much alcohol)

Sometimes, what feels like a hesitation is actually ignition misfire rather than lean misfire. The causes of ignition misfire may include:

Dirty or worn spark plugs
Bad plug wires
Weak ignition

I located the sales receipt from the tune-up. It states that the work done was:

Engine diagnostic
Fuel injection/mass Air Cleaning
Flow and throttle body decarbon
Fuel filter replace

What should I check now? Could it be the catalytic converter? Should I try spark plugs first?

Should I try spark plugs first? Do so and check the fuel pressure and the throttle position sensor

It was the catalytic converter. Still covered under the warranty. Nothing beats free. I saw people (online) had the same problem and payed for it, my only advice is check with a dealer or your warranty.