Hey Scotty/anyone else,
I have a 2014 Tundra 5.7L V8 with 35k miles. My check engine light keeps coming on and when I read the codes from my diagnostic scanner it says that every cylinder is misfiring. Sometimes the engine idles hard and then switching into drive it stops. Other times vice versa. You can tell the engine is misfiring. I feel like I have done everything. I've: changed all 8 sparkplugs, all 8 ignition coils, the MAF sensor, crankshaft sensor, and it has a new battery. I took it to a local shop and ($400+) later they said it was the MAF again, even though the one I put in there was only about 3 weeks old. I'm at a loss of what the issue can be. Once I clear the codes out it may drive fine for a day but then it throws the code again. Any suggestions?
Did you use an OEM MAF sensor? Also, if you haven’t already, check this sticky for other possible causes:
https://carkiller.com/scottykilmer/qa/misfire-4/
Yes, I looked up the senor on rockAuto and bought the same one that was already in the truck. Thanks I will check out that link!
Are you just getting a P0300 code or is it accompanied by misfire codes for each individual cylinder?
Why does the "local shop" suspect the MAF sensor?
What's your MAF sensor reporting at idle?
It should be around 1 gram per second per liter of engine displacement.
So your 5.7 L engine should be around 6g/s (+or- 0.5g/s)
If your MAF is faulty enough to be causing misfires you should also see excessive fuel trim corrections.
Look at your fuel trims.
Maybe post your Freeze Frame Data from when it throws these codes.
Also, is your Tundra flex fuel?
If it is, what percentage of fuel alcohol content is it reporting?
