P0172 running rich

[dwlawson]

2010 tsi with CBZB engine. The engine light is on and I get code P0172, running rich. It can't be that rich as it runs fine and gets 56mpg. So far I've changed air filter, fuel filter, spark plugs and first oxygen sensor with no luck. I'm using the free version of Car Scanner on my phone. If I invest in a paid diagnostic scanner like VCDS or obdeleven will that give me more specific information on what is wrong?

[Johntheo1]

You could renew the (engine breather) PCV valve, check for any cracked hoses first and if that doesn't cure the problem, the charcoal filter solenoid.valve.

[dwlawson]

I've renewed the fuel breather valve as I could blow through it both ways. The PCV valve seems ok; I can blow through it one way but not the other.No cracked hoses.
I've noticed the timing chain is noisy all the time, not just when starting. Can it stretch sufficiently to cause a P0172 fault code?

[Retali]

2010 tsi with CBZB engine. The engine light is on and I get code P0172, running rich. It can't be that rich as it runs fine and gets 56mpg. So far I've changed air filter, fuel filter, spark plugs and first oxygen sensor with no luck. I'm using the free version of Car Scanner on my phone. If I invest in a paid diagnostic scanner like VCDS or obdeleven will that give me more specific information on what is wrong?

I own obdeleven , there are some live data you can run . VCDS is by far better. But you need to know what live data to run and how to read them.


It could be injectors, fuel pumps (high pressure or low pressure ) etc.

Does your oil smell gasoline ?

[dwlawson]

Yes I can smell petrol at the oil filler with the engine running. I've now got an obdeleven. What tests can I run?

[Retali]

Yes I can smell petrol at the oil filler with the engine running. I've now got an obdeleven. What tests can I run?

i do not even know man ! You have to keep searching a bit.

From one of my posts (cause i honestly dont remember) i found this

"I used obd scanner and checked the high fuell pressure actual value, and it was 45000 kpa with engine on and running. When i switch the engine off, the value remained the same
and i when i switched the engine on and running again the value increased for a moment and then it went back to 45k kpa.
The fact the value it did not drop when i switched it off, means according to what i have watched, that the injection is not leaking pressure"

[dwlawson]

I measured fuel pressure as 4500kPa then switched the engine off. Switched ignition back on so the obd dongle had power. The pressure slowly increased to 10000kPa and was still going up when I restarted and pressure immediately dropped back to 4500kPa. So what is this telling me?

[Retali]

I measured fuel pressure as 4500kPa then switched the engine off. Switched ignition back on so the obd dongle had power. The pressure slowly increased to 10000kPa and was still going up when I restarted and pressure immediately dropped back to 4500kPa. So what is this telling me?

according to what you experienced, it is the same as mime, you did not lose pressure (pressure did not drop from 4500kpa but got higher) from the injectors so they are no leaking i guess. That is why i used that as far as i can remember.

Maybe checke the voltage of the o2 sensors afterwards, i will do today to. According to google, if the voltage is unstable and erratic=problems.