What causes the P0191 code on the L5P, and how much is it going to cost me?

[OilSlickSam]

My 2019 just threw a P0191 (Fuel Rail Pressure Sensor) code and went into reduced power mode. What is the deal with these sensors? I’ve heard they are a nightmare to get to because they are buried under the intake. How is everyone handling this—are you letting the dealer do it under warranty or is it a DIY job?

 

[OutbackIron]

It’s a known issue on the 2017-2019 trucks. The harness or the sensor itself fails. How you fix it depends on your patience; you have to pull the top of the engine apart to reach it. If you’re out of warranty, expect to pay a shop 6-8 hours of labor. Most guys replace the whole fuel rail harness while they are in there.

 

[DailyDriven]

Sorry to hear it, man. What you’re dealing with is a classic L5P headache. Usually, it’s not just the Fuel Rail Pressure (FRP) sensor that fails—it’s the wiring harness itself. The factory harness is pulled too tight and rubs against the engine, causing an intermittent short.

How everyone is handling this: If you're still under the 5-year/100k mile powertrain warranty, get it to the dealer immediately. If not, be prepared for a $1,200+ bill. Most of that is labor because, like you said, it’s buried under the fuel rails and intake plumbing. Don't just replace the sensor; make sure they install the updated harness pigtail or you'll be doing this again in 6 months.