How JustAnswer Works:
  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site.
    Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.
Ask I. Silva Your Own Question
I. Silva
I. Silva, VW Technician
Category: VW
Satisfied Customers: 1603
Experience:  auto mechanic
46707633
Type Your VW Question Here...
I. Silva is online now
A new question is answered every 9 seconds

My 03 vw passat has 6 codes in the computor p0171 p0300

Customer Question

My 03 vw passat has 6 codes in the computor
p0171
p0300
p0301
p0303
p0304
p0302
Submitted: 1 year ago.
Category: VW
Expert:  I. Silva replied 1 year ago.

Hello...welcome and thank you for using Justanswer.

The 300's codes are for engine misfiring ,the code P0171 is a lean code ,the engine is running with the wrong mix(air/fuel)

The most common problem for the lean code is a vacuum leak,i would check for any broken/disconnected vacuum hoses.

The Mass Air flow sensor is another possible problem that sets the P0171 and also can create this misfiring codes.

The fuel pressure or poor quality gas (water in the gas) is another possibility.

Do you feel the engine running rough ?

Have you try to clear the codes and drive the vehicle again to see what codes comeback?

Good luck.

Let me know.

Thank you very much.

Customer: replied 1 year ago.
I just cleared the codes tonight, it idles very rough and the check engine light starts flashes
Expert:  I. Silva replied 1 year ago.

Ok, so you do have a misfire ,can you read the codes to see what comes up first?

This is the 4 cylinder engine right ?

Let me know.

Thank you.

Customer: replied 1 year ago.
This is a 1.8 turbo. Havent had a chance to drive it yet.(to cold to be stranded). I have noticed that when i start it cold it doesn't come up on high idle.
Expert:  I. Silva replied 1 year ago.

Hi there...sorry for the wait.

Scan the engine again to see what codes came back, if you have just 1 or two misfiring codes ,swap the coil from the bad cylinder with another cylinder that is working.

Clear the codes and run the engine again, if the code changes to the cylinder you put the possible bad coil ....you know you need a new coil , if it stays as the same code...check the spark plug, if good...you will need a new ignition module , located on passenger side by the air filter box,it has two connectors to it and is secured with two screws.

Good luck.

Let me know.

Thank you very much.

Customer: replied 1 year ago.
It was a broken vacumn T under the intake manifold.
Expert:  I. Silva replied 1 year ago.

Hi there, I am glad you fix the problem.

Like I said on my first post ,the P0171 is for lean code and the most common for lean code is a vacuum leak , it must be a pretty large vacuum leak to make the engine misfire that bad.

Please rate my answer if I have helped, positive rates are really appreciated and do help the techs at this site.

Thank you very much.

Related VW Questions