Rich codes

[Peanut1408]

I have a 2014 5.3l with ppo172and p0175 both banks rich thought was in injectors so I put all new ones in no change still throws codes and does the dieseling and can smell fuel in exhaust anybody had this problem with a actual fix 

[tbarn]

Now that had to be an expensive experiment. Is there fuel in the oil? Same symptoms on a 4cyl Equinox would take me directly to a high pressure fuel pump. Same basic pump.

[1SLOW1500]

I would check O2 sensors first As something is telling the computer to add fuel. If it is the down stream vs the up stream. Many things can demand fuel Maf being one of them But it has many codes for that. These truck run rich from the factory but to throw codes...... It could be as simple as air Getting to the o2 but again don't think so. 

[Peanut1408]

I already changed up stream o2s and oil doesn't smell like fuel 

[2017Darkness]

 

Involved Region or Country

North America

Condition

A vehicle may have a concern with a SES lamp on and a rich running condition DTC's P0172 and P0175.

Cause

Possible high pressure fuel pump 

Correction

If SI does not Isolate the cause of the rich condition the following may be help full. 

Disconnect the dirty air side of the PCV system 

Plug the vacuum supply 

Start the engine and monitor the fuel trims in closed loop. 

If the fuel trims return to normal this is a good indicator that the high pressure fuel pump is leaking. 

With this concern we do not see a lot of fuel in the crank case, so changing the oil may not isolate the concern. 

When the high pressure fuel pump leaks the PCV will pull the fuel mist straight into the intake causing the concern.  

Note: This is a preliminary temporary diagnostic and repair.

As more investigation information becomes available this PI will be updated or advanced to a bulletin.

 

[Sierra Jon]

I have a '14 5.3 and it just starting throwing this code this past summer. I just got 100k miles. It happens when I let the truck idle for 15 minutes or more (while hooking up my TT) but the CEL turns off after a couple normal drives.

My truck has a Diablo tune btw but I don't think that's the RC.

[tarheeld]

Have had the same issue with my 2015 Yukon. Stealership says its the High Pressure Fuel Pump. Get it fixed pronto.