My 2017 Mazda6 automatic non turbo model has a sporadic hesitation issue. When it happens it will be after the car sat overnight. When I leave my neighborhood and turn on the 50 mph road I press the gas pedal and my car will barely move and after about 2 or 3 seconds I feel the power start to return and then the car will accelerate normally. The car never seems to hesitate more than 1 time in a given day. It did this last summer and once fall/winter came the issue stopped. Now that the weather is warming again the hesitation issue is coming back. I have replaced the air filter and spark plugs. I have cleaned the mass airflow sensor. My car has 110,000 miles on it.
What about the fuel filter? Did you check fuel pressure? Any vacuum leaks? Have you performed a diagnostic scan for codes and live data?
I did a scan with my cheapo scan tool and there were no codes and no lights have come on either.
That's really not relevant. What's in the data? What do your fuel trims look like? (Most cheap scan tools can read live data. You need to learn how to do that to work on modern cars. There are plenty of youtube videos, including Scotty's, demonstrating how to do that.)
I didn't think of vacuum leaks...I'll look for a diagram so I know where to find the vacuum line/lines.
You should be able to see vacuum lines in the engine compartment. The intake manifold gasket should also be checked. (You can use the carb cleaner trick to help find vacuum leaks.)
Another thing you can do if you have not done so already is to clean the throttle body.
I don't know how to check the fuel pressure and I haven't checked the fuel filter.
If there is insufficient fuel flow due to low pressure that should show up in the fuel trims. The fuel filter is built into the feeder pump in the tank.
The GDI high pressure should be listed in live data. The low pressure feeder pump may also be listed, otherwise a fuel pressure gauge would need to be attached.
It is also possible that you're experiencing a transmission problem. Has the transmission been regularly serviced? That should have been done at least once if not twice at that mileage. When the car fails to accelerate does the engine rev up and the car fails to move, or does the engine bog down?
I did a scan with my cheapo scan tool and there were no codes and no lights have come on either. I didn't think of vacuum leaks...I'll look for a diagram so I know where to find the vacuum line/lines. I'm a novice.....I don't know how to check the fuel pressure and I haven't checked the fuel filter. I assume the fuel filter is located in the fuel tank?