Sunday morning 12/15 took the truck out and it randomly starting tapping loudly at the gas station while filling up and CEL came on. I was only a couple of miles from home so I went back home and checked the codes (p3400 cyl deactivation bank 1, p0304 #4 misfire, and p1414). Stupidly I did an oil change (redline) yesterday 12/17 thinking it might help because the truck had occasionally thrown a p0304 code when I was due for an oil change. No change.
Truck has about 155k miles. No prior engine issues. Noticed the "tick around 100-120k" and switched to using Redline oil and haven't heard it since.
Swapped the coils on the 2 & 4 cylinder, and installed new NGK IR plugs. No change.
Next step is replacing the MDS solenoids however, I do speculate its a cam/lifter issue.
That being said I am having a hard time searching for the best kit to use. If needed should I go with the MMX kit? I hear bad things about Rockauto. Not even sure where to look at this point.
