Re: sputtering during acceleration
I would first check the fuel pressure at the rail, should be 49 +- 5 PSI. If much lower, then first change the fuel filter/pressure regulator.
Is the regular maintenance up to date? Plugs, air filter etc?
If you have a scanner which shows live data, then you can check the fuel trim figures and the O2 sensor voltage. A faulty O2 sensor can cause a too lean mixture, however normally you would get multiple misfire codes for that. Did you check for any fault code set? You can do that using the key dance: ignition switch off/run three times and leave in run at the third time. Odometer will show DONE or any fault code(s).
Finally could be a partly plugged catalyser.