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Dan, Technician
Category: VW
Satisfied Customers: 24460
Experience:  Independent Shop Experience, 2 Year Automotive Diploma, & Access to Information Database
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I have a p0172 code on my 2001 vw jetta 1.8t wolfsburg. Engine AWW.

Customer Question

I have a p0172 code on my 2001 vw jetta 1.8t wolfsburg. Engine AWW. I've cleand then replaced my MAF sensor and cleaned the air filter, I've ran fuel injector cleaner and done a tune up.. Would it be an oxygen sensor, for fuel system running rich?
Submitted: 8 years ago.
Category: VW
Expert:  Dan replied 8 years ago.

There are quite a few possible reasons, but the upstream oxygen sensor is common and would be a good place to start. Some other common failures: faulty vacuum lines to the fuel pressure regulator, sticking fuel pressure regulators or a sticking N80 canister control valve. Let me know if you have questions, thanks.


Potential Causes:Contaminated Engine Oil - Engine oil is fuel saturated.
Defective Fuel Pressure Regulator
Broken Fuel Pressure Regulator Vacuum Line
Restricted Intake Screens
Defective N80 Canister Control Valve
Defective Upstream Oxygen (O2) Sensor