^^ I'd sure like to know what this turns out to be. Please be sure and follow up here if you can.

 

ok guys, new issues but im almost 100% that its related....SES light on, code is p0172, something to the effect of air/fuel mixture too rich....gonna troubleshoot further when i get a couple days off

 

Well, the only thing in the possible causes that seems like it could be related is the fuel pressure. Other than that, I don't see a correlation. It may just be coincidental.

How is it running? Are you noticing symptoms of running too rich?


P0172 System Too Rich Bank 1
Symptoms

- Engine Light ON (or Service Engine Soon Warning Light)
- Excessive Fuel Consumption
Possible causes

- Faulty front heated oxygen sensor
- Ignition misfiring
- Faulty fuel injectors
- Exhaust gas leaks
- Incorrect fuel pressure
- Faulty Mass Air Flow (MAF) sensor
When is the code detected?

- Fuel injection system does not operate properly.
- The amount of mixture ratio compensation is too large. (The mixture ratio is too rich.)
P0172 Description

With the Air/Fuel Mixture Ratio Self-Learning Control, the actual mixture ratio can be brought closely to the theoretical mixture ratio based on the mixture ratio feedback signal from the heated oxygen sensors 1. The Engine Control Module (ECM) calculates the necessary compensation to correct the offset between the actual and the theoretical ratios.

In case the amount of the compensation value is extremely large (The actual mixture ratio is too lean.), the ECM judges the condition as the fuel injection system malfunction and light up the MIL (2 trip detection logic).
What does that mean?

Basically this means that an oxygen sensor in bank 1 detected a rich condition (too little oxygen in the exhaust). On V6/V8/V10 engines, Bank 1 is the side of the engine that has cylinder #1.

Note: This DTC is very similar to P0175, and in fact your vehicle may show both codes at the same time.
Symptoms

You will more than likely not notice any drivability problems, although there may be symptoms such as a misfire.
Causes

A code P0172 may mean that one or more of the following has happened:

The MAF (Mass Air Flow) Sensor is dirty or faulty. Note: The use of "oiled" air filters can cause the MAF to become dirty if the filter is over-oiled. There is also an issue with some vehicles where the MAF sensors leak the silicone potting material used to protect the circuitry.
There could be a vacuum leak.
There could be a fuel pressure or delivery problem

Possible Solutions

Possible solutions include:

Inspect all vacuum and PCV hoses, replace if necessary
Cleanthe MAF sensor. Consult your service manual for it's location if you need help. I find it's best to take it off and spray it with electronics cleaner or brake cleaner. Make sure you are careful not to damage the MAF sensor, and make sure it's dry before reinstalling
Inspect fuel lines for cracks, leaks, or pinches
Check the fuel pressure at the fuel rail
Check the fuel injectors, they may be dirty. Use fuel injector cleaner or get them professionally cleaned/replaced.
Check for an exhaust leak before the first oxygen sensor (this is unlikely to cause the problem, but it is possible)

 

thanks vq, will try

 

Bump.

I have the same issue. Sounds like an EVAP issue.

Does anyone know how to check the EVAP system to clear any clogs?