Need help,PLEASE!

[David j Robbins]

I have a 2018 6.4l 2500 Ram with 175,000 miles I keep seeing a po430 code sometimes accompanied with a po308,I have just replaced all plugs and have just recently replaced #8 coil pack,I don't hear or see any exhaust leaks?any ideas or patterns seen in these trucks other than the dreaded cam and lifter failure,seems to be getting a couple mph difference (lower) Little difference if any noticeable power loss??? Any and all help would be greatly appreciated!

 

[Sandevino]

P0308 is cylinder 8 misfire
- pull and check the plug and wire.
- switch the coil from cylinder 6 to 8 and vice versa and see if the code follows.
- if the code follows the coil replace it

P0430 is three-way catalytic converter functioning below threshold
- this is usually a bad downstream oxygen sensor more than a failed cat.

Resolve the misfire first then go after the oxygen sensor.

 

[danoday]

In addition to what's been said already, pull your oil fill cap and smell for fuel. A fuel injector stuck open can cause a misfire as well.

Sent from my SAMSUNG-SM-N910A using Tapatalk

 

[MADDOG]

The sensor problem might be caused by a dead cylinder. If #8 isn't firing correctly, or even at all, excess hydrocarbons are being pumped into the exhaust gas.

Swap the #8 coil to #6, clear the codes and then run the truck. If the next code comes up P0306 then it's the coil. If it's still P0308, then the wire, the connection to the plug or the plug itself is the culprit. You can move the wire and the plug, independently, to #6 and test further.