P0303 check engine light is on.

p0171 = fuel system too lean, this means vacuum leak or faulty oxygen sensor

p0303 = cylinder 3 misfire

p0325 = knock sensor malfunction.

p0303 and p0325 - i can see these working together, if a cylinder misfires, it will cause the knock sensor to trip. I would lean towards the coil and or ignition module, along with a faulty oxygen sensor.

you have multiple cylinder missfire 1,2,3,5 check your spark plugs, plug wires and coils could even be a o2 sensor

All of these codes are misfire codes.clicking sound is most likely spark jump from plug wires to metal(head,block,valve cover etc.)

p0303 is a mutible engine misfire on number 3 cylinder. the best fix,

A code P0303 may mean that one or more of the following has happened:

• Faulty spark plug or wire
• Faulty coil (pack)
• Faulty oxygen sensor(s)
• Faulty fuel injector
• Burned exhaust valve
• Faulty catalytic converter(s)
• Running out of fuel
• Poor compression
• but first of all check the wires and sparkplugs first!

Cylinder 3 Misfire Detected is a P0303

P0303 mean Cylinder 3 Misfire.

Consider replacing the Cylinder 3 Spark Plug. If that does not settle it,replace the wires too.

Good luck.

P0171 is LEAN and P0303 is misfire number 3 cyl. Its time to stop guessing and pay for a correct diagnosis. Find a shop that works on VW and has the tools to work on it. DO NOT put those Bosch Platinum Spark plugs in that Ottozone tries to sell everybody.

The Specific code "P0303" is stating that the Third Cylinder or Cylinder number 3 Is mis-firing, thanks to all that you have done this has narrowed it down to two "confirmed" possible problems;

The first is that the Exhaust VALVE itself may be "Burned" and the Second may be a Poor condition or "Faulty" Catalytic converter(s).

This is only a possible cause but please keep in mind that on some certain models (not too sure about this specific model) there are multiple O2 Sensors located in different spots. (usually in or next to the preliminary and primary catalytic converts)

Also one of my experiences lead me to beleive that the Ignition Control Module (ICM) may be faulty causing the injector to not provide proper Fuel to the Cylinder.which will more often than not cause the computer chip to sense the misfiring as opposed to the bad signal from the ICM.

Hope it helps you out, and good luck.

p0456--emission control system leak(verysmall) leak, check all hoses to emission controls, cylinder 3 missfire detected. could be plugs, wires, or coil.this is code p0303,

coils, injectors, or plugs. need more info.