Originally Posted by
Cozzm0
The MAF is usually attached to the Airbox with a separate Intake Temp Sensor on the GA series motors i believe, but we don't have the GA15 in Australia, only GA16. Sometimes the single wire Oxygen sensor used on the GA goes bad as they rely on the exhaust temp to heat them up (instead of the 3 wire heated version used on the SR). This might also be giving 'bad feedback' to the ECU and causing hesitations.
Make sure anything you use on the MAF is designed for it, using harsh cleaners like throttle body cleaner can damage the air flow sensors.
Might be worth checking for cracks/leaks in intake pipe too as any kind of vacuum leak can make the car run quite lean which makes it feel like its being held back.
Disconnecting the battery and reconnecting it after a short time (couple of minutes) can also reset the ECU self learning / fuel trim which if the O2 sensor is bad, even if replaced, will maintain some of the hesitation feeling if the fuel trim isn't cleared out (with laptop connection or by disconnecting battery).