Drove in to work. Misfiring and low on power(i live in a very hilly area. Ran a quick scan same codes as before. P0306, P0303, P0300, P0171, and P0174.....thinking maybe plugged injectors. When struggling to pull the hills, i would floor it and eventually it picked up and had normal power....then same thing on the next hill
Thanks for the update.
One thing I forgot to say is, the fuel system cleaner I always use is BG44K.
Sometimes I use JECTRON.
But nothing else, b/c nothing else is as good as those.
Maybe try using BG to clean out your system.
But remember that these cleaners will clog your injector screens, and NOT clean your injectors.
If you replace all your injectors, then your best bet is to remember to flush the main fuel line.
Just connect a hose to it and put it in a large container and run the fuel pump for a few seconds.
Then take a look at the container to see if any garbage is in it.
If not, then I would also inspect the fuel rail, b/c it may be rusty inside if the previous owner used ETHANOL and let it sit.
The water separation will wreak havoc on those steel lines.
One thing I really like about this truck is how well it runs.
It's better than any other vehicle I've worked on, including Hondas.
So if #4 & #6 are misfiring, then I would do a 'cylinder balance' test 2 ways to verify whether it's fuel or spark:
1. turn off each cylinder's spark using the 'pull the wire' test (being sure to ground the distributor tower where the wire's off)
2. turn off each cylinder's fuel using your scanner.
Do each test one cylinder at a time.
If you 'suspect' it's fuel, then do that test first.
It won't take more than 10 minutes.