My 2011 RAM 6.7 drives me nuts with an intermittent P0191 error code (often along with a P2BAC code) that I seem not to be able to get under control. As it seems not to have too much effect on fuel mileage and acceleration I couldn't care less for the most part, but when it comes to doing smog in California it becomes the bi-annual proverbial pain in the behind ...

The truck is bone stock with120kmls, only mod is an upgrade to an AFE Power intake.
I am changing the main filter every 5kmls, which should have kept my fuel delivery system clean. The truck does not have a pre-filter underneath it other than probably the one in the tank.
I had the fuel rail pressure sensor replaced at one of the previous smog tests, the ECM was flashed to the latest version as well, all to no avail.
The tech in my shop of choice looked up that replacement of all injectors plus connectors should possibly take care of it, but at an estimated whooping $4500 for the job it's quite the bill to get rid of a service engine light and computer entry to pass smog.
I looked into replacement of the stock fuel rail plug with one from BD Diesel in Canada, but am not certain if it has the desired effect.
I am at a loss of feasible option.

Anybody with some effective advice what to try next?

 

The P0191 is whining about rail pressure..... Seems its getting an 'irrational' value. Have a scanner you can plug in, and see what the PCM is getting for rail pressure? That would be interesting to know. The second code is very likely to simply be a result of what is causing the first..... Fix the first one, and the second should resolve itself.

I doubt replacing the injectors and such will change anything, and spending that kind of money to have zero effect? Nope. Can't justify that....