Help diagnose engine codes P0300, P0301, P0306, P1604

Hi guys. So I'm having issues with my truck (2012 V6 TRD OR, auto, 72k miles). Yesterday while stuck in traffic I felt it sputter and loose power between 1,500 to 2,100 RPM. Kinda felt like a transmission issue since it was only happening in the transmissions "sweet spot" for gear changes. Drive a couple more minutes, sputtering gets worse and starts shaking and sounding like a small boat/motorcycle engine; Trac Off and CEL light start flashing. I pull over, restart the truck and both lights are gone and the truck feels fine. Keep driving it home and I can still feel a slight sputter every now and then under the same conditions but it doesn't "engage" the feel and sound that had happened before. Being closer to home, and knowing this issue isn't resolved, I decided to take it around the block and reenact the conditions. I managed to make it happen again (feel, sound and dash lights). I pull over and restart it, the lights stay on (not flashing) this time but the engine feels fine. Park it at home and start reading up on TW.

According to other threads, I checked my fuel gas cap was properly tightened, I sprayed carb cleaner around intake hoses to check for vacuum leaks, checked MAF connections and plug coils where on tight. That didn't seem to be the culprit since I reset the ECU afterwards by disconnecting the battery to clear the codes and drove to pep boys to get a scanner on it, on the way over there it started misfiring again (flashing CEL), pulled over and restarted the truck. It kept running ok and the lights didn't stay on, I actually got to pep boys without any issue, so I decided to drive around the block a couple times and managed to get the spuuter and the light on again.

Anyway, code scan results (from a picture on their reader):
P0301 - Cylinder 1 Misfire Detected
P1604 - Start Ability Malfunction
------- - Engine - Pending codes
P0300 - Random / Multiple Cylinder Misfire Detected
P0301 - Cylinder 1 Misfire Detected
P0306 - Cylinder 6 Misfire Detected

Drove it back home and a couple blocks out it started idling fairly rough (misfires), pulled over to restart the truck hoping it would "reset" like it had before but it didn't. So I did my best to baby it back home.

Full disclosure, about to weeks ago I went on a snowy camping trip, there was a lot of mud so I had the engine bay washed (maybe they used a pressure washer that screwed something up?). And about a week ago I cleaned the throttle body and MAF sensor according to a thread I saw on TW and was really careful not to damage the MAF sensor (didn't touch it and only used MAF cleaner), reinstalled it after it dried.

So I think from other threads I've read, I shouldn't be concerned with the P1604 code, since it seems to be random and sometimes related to starting/stalling (which my truck does not have an issue with) and many have said to ignore it or that it's only related to government compliance. The other codes have prompted me to start checking plugs, coils and/or wires which is what I'm about to do since it's consistent with misfires, but I'm also thinking it might be crud from the throttle body cleaning clogging my injectors? So I'm not sure if I should limp the truck to my nearest gas station, and refill with 91 octane plus an injector cleaner. So if it's bad gas/dirty injectors this may take care of it?

Any helpful advice on my issues, troubleshooting, things to check and ways to check them are appreciated.

Thanks!

 

Try swapping coils 1 and 6 to different cylinders. See if you get the same codes.

 

I had the same codes a couple months back an it was number 6 coil was bad. Replaced an she is good to go.

 

Started digging into the truck. Get to cyl. 1 to check the plug, remove the coil and see some weird white "mineralish" stains on it. Shined my light at the plug and yep! There's water in the coil bucket or plug chute, whatever that's called. So now I'm going to check all plugs to see if they're flooded as well. I'm rolling a paper towel into the coil bucket and blasting it with compressed air to get the water out, not sure if there is a more efficient method of doing this, I'll leave the coils out so the remaining water can hopefully evaporate over night before taking the plugs out to check them. Do you guys think coils, plugs may be salvageable?

 

Your coils and plugs are probably fine....

 

So I dried and cleaned coil #1 and only cleaned inspected #6 (it didn't have any water in it), checked plugs on 1 and 6 and they looked perfect, swapped coil 1 with 3 and 4 with 6. Took it for a spin and it felt fine, drove to the gas station, filled up with 91 octane and an injector cleaner just in case. So far no shakes or rattles and no CEL. Still very suspicious about this problem being solved. Should i just keep driving and see if anything pops up or is there something else I could test?

 

Just drive it and see. The water was probably the issue shorting out the spark plug.