Hi Scotty,
I have a 2021 Toyota Corolla Hatchback with 2.0 motor and 6speed manual.
Under full load, (acceleration or going up hill ) the engine stumbles /acts like it's not getting enough fuel..if I do not let off the throttle the misfire code is generated.
I checked for vacuum leaks with smoke. No leaks.
Is it the direct injectors or coils faulty.
Only 56000 miles.
Thank you for your time.
Although it shouldn't be needed on a car that new you could try cleaning the throttle body and MAF sensor. As @justin-shepherd says though you really should record live data for analysis while the problem is happening, see what fuel trims and other data look like to get clues as to what's going on.
Also I don't know how long Toyota's warranty is on that car but if it is still within the warranty period the dealer should really take care of it.
https://www.youtube.com/watch?v=NWCKvU2FmDc
It could be either. What are your fuel trims like when you're going uphill? When you're going uphill, I'm pretty sure the car should run slightly more rich (more fuel, less air). The fuel trims should increase slightly when it's under load.
check spark plug gap , clean or replace them if needed. clean air filter or replace if needed.
could be a lose ignition coil (spark plug) wire
or
carbon build between spark plug and coil/wire disconnect the battery before working on any of these steps .
Was the issue an ignition coil? Running into this now and seems to be consensus out there.
@macmike78 The person you are asking posted this topic nearly 2 years ago and has not been active since then - so you are unlikely to get an answer from him.
Instead of "hijacking" someone else's topic please post your own including all vehicle details, a clear and concise description of your car problem, and the diagnostic steps taken so far. Thank you.