Trouble code P0300,P0301,P0303

Hello everybody , I have a 2002 Toyota Tacoma 2.7L ,mileage 274,000 miles and I've had a few trouble codes pop up recently P0300,P0301,and P0303.
random misfire ,misfire in cylinder 1 and 3

I can't pin point where the issue is coming from, I have a list of thing I've done and replaced,
-new oem Denso ignition coils
-ngk spark plugs
-cleaned throttle body and new throttle body pos sensor
-new injectors because old ones were cracked and leaking fuel
-new maf sensor
-I've inspected all of my rubber hose and I don't see any that are rotted or cracked
-I've also change my fuel filter and my fuel pump due to previous issues regarding that

Engine idles rough as well as some shaking and I believe somewhat loss of power, when accelerating I don't really notice shaking from engine.

was wondering is anyone else has experienced this issue ,is so could you please help me out and leave a response of what it could be, thank you.

 

I ended up finding my p0300 fix using this flow chart for the 3rz. http://www.markofshame.com/fsm/03_Tacoma/Repair_Manual/03tacoma/di/eg2rzfe3/cip0300p.pdf

I went through the whole guide and never found it. Then went through starting step 1 again being much more careful on my examinations. I ended up finding my vacuum leak using a home made smoke machine.

 

Excellent diagnostic link… I did not know that at high engine speed that individual cylinder misfire count is disabled.

 

thank you for the documents I will definitely use this as well as look into using a smoke machine to see if there is a vacuum leak as well instead of just eyeballing it ,once i do i will come back with results. thank you

 

you can also spray a little starter fluid around the bay and listen for idle increases. Did this problem start randomly? Or after replacing injectors etc?

unrelated, what were your symptoms with leaking fuel injectors? Hard to start after running hot?

 

Excellent Q^^^

 

i think it may be the EGR valve.
I have the same problem. it only happens when i start the vehicle in the morning. i can sometimes evade the codes and such by throttling up a bit till it idles normal. then it runs good all day.
i have done all you said as well yet it still happens.

what did you end up doing?