I recently bought a 2015 Silverado 1500 with 119k with a p0430 thinking it was just a cat problem and that I don’t care if extra fumes are getting into the atmosphere. Well I’m now reading that that is caused by something worse going on in engine. Roughly a week into owning the truck while under load it threw a p0300 as well as a p0306 I took it back to dealership I bought it from and they replaced the cylinder 6 injector for free. No more miss fire truck was running good. I’m wondering if the leaky injector and exes fuel caused the bank two to clog up? Now my truck is taking a long time to crank over in the mornings, much longer than normal, and the other day my truck was idling for a while and I got the p0172 and p0175 codes, I checked my long term fuel trims and both banks were -30. From the research Ive done I’m thinking the high pressure fuel pump has gone out. Wondering what y’all’s thoughts are on that? Should I proceed with replacing it? Another thing I noticed while I was doing my oil change was the color seemed off and it had a little bit of mental in it, I’ve read a leaky high pressure fuel pump leaks gas into the crank case witch would thin out the oil. I am wondering if all these problems are related thank you!

 

You don’t need to be concerned about the P0430 just yet - with the system lean codes, any converter efficiency codes need to be ignored until the lean codes are resolved.

To verify if there’s fuel getting into the oil, drive until the engine is up to temperature, then disconnect the PCV valve hose, cap off the intake port, and monitor fuel trims at idle. It won’t hurt anything to vent the PCV to the engine bay during this test.

If there’s fuel getting trims return to normal, replace the pump.

Make sure to properly torque the HP fuel line fittings to the proper specifications. Fuel will leak from the connections if they’re not properly tightened.

I can provide further instructions if needed.