I’ve researched the heck out of these but the codes seem to be super vague. I swapped out the spark plug on cylinder 6 but got 0306 again. Did notice what looked like oil in that cyl. A little wet.

 

Almost none of us memorize the code numbers meanings outside of the 03's. Good to give us a quick summary of their meanings, then we can help.

Cylinder misfires can be caused by improper amounts of fuel, ignition, or compression. Coils, injectors, rockers, cam, piston rings, could be a dozen things. The other codes are your clue.

 

Best troubleshooting is process of elimination - swap known good in to questionable position.

 

P1171 and P1174 are lean codes typically caused by a vacuum leak. They cause the ECM to dump more fuel via the injectors in a futile attempt to bring the air-fuel ratio back to where it should be. The excessive fuel can then cause misfires (P0300 & P0306). I've seen exactly these conditions in a friend's DII several years ago.

You can diagnose a vacuum leak with a smoke test. There are "smoke" machines, but I did it on the friend's DII the old fashioned way - with a cigar and a short length of tubing connected to a port on the upper intake manifold. Worked like a charm.

 

Okay, It does take a long while of driving for the codes to pop back up and when accelerating the truck runs fine, just at idle when it sounds rough. Time to try the smoke test for sure! Ty

 

So thought I pin pointed my issue to a o2 sensor. My live stream of the motor running showed the b2 s1 was low on voltage so I replaced it but now it shows no voltage. Also found that there’s coolant dripping from the rear of the motor. Looked all over, no leaks at the heater core hoses.

 

Also, coolant is fresh looking where it’s dripping from

 

Again, your truck has a vacuum leak. The misfires and O2 codes are because of the vacuum leak.

Do a smoke test to find the vacuum leak and address that. The misfires and O2 sensor codes will likely then go away. Replacing the O2 sensor was likely money wasted. Keep the one you removed to have as a spare.

The coolant leak is a separate issue. On which side is the coolant dripping from the rear of the engine?

 

Tore into the top end and found my coolant leak at the front top of the intake manifold. Also found that the secondary air ports at each head where a bit loose. Tightened those up. Ordered rebuilt injectors, upper intake gasket. Also found that my steering pump and pump hose where leaking pretty good. Ordered a new pump and both hoses. Hoping this will all will get me going again.

 

The loose SAI fittings could certainly be the source of the vacuum leak, depending on how loose they were. Good luck, and please follow up here once you have the truck back together and with a few miles on it.