P0303, P0304, P0401, P0420 Audi vehicle fault codes

We are an award winning independent garage that can service your Audi vehicle fault codes. We invest in all of the latest Audi tech that will help us get to the heart of the problem your Audi is experiencing at our garage workshop pictured below.

A break down of Audi fault codes your P0303, P0304, P0401, P0420 experiencing

P0303 Worn out spark plugs, ignition wires, coil(s), distributor cap and rotor (when applicable), Incorrect ignition timing, Vacuum leak(s), Low or weak fuel pressure, Improperly functioning EGR system, Defective Mass Air Flow Sensor, Defective Crankshaft and/or Camshaft Sensor, Defective Throttle Position Sensor, Mechanical engine problems (i.e.—low compression, leaking head gasket(s), or valve problems)

P0304 Worn out spark plugs, ignition wires, coil(s), distributor cap and rotor (when applicable), Incorrect ignition timing, Vacuum leak(s), Low or weak fuel pressure, Improperly functioning EGR system, Defective Mass Air Flow Sensor, Defective Crankshaft and/or Camshaft Sensor, Defective Throttle Position Sensor, Mechanical engine problems (i.e.—low compression, leaking head gasket(s), or valve problems)

P0401 Restriction in the EGR passages, usually caused by carbon buildup, The EGR Valve is defective, Lack of proper vacuum or electrical signal to the EGR valve, Malfunctioning EGR Vacuum supply solenoid, Lack of proper EGR system feedback to the computer from the: Manifold Absolute Pressure Sensor (MAP), Differential EGR Pressure Feedback Sensor (DPFE), EGR Valve Position Sensor (EVP), EGR Temperature Sensor

P0420 Inefficient Catalytic Converter(s), Defective Front or Rear Oxygen Sensor(s), Misfiring engines

Contact us

If you need to diagnose any of the following Audi fault codes P0010, P0011, P0012, P0013, P0014, P0101, P0102 then call us. We have the dealer level tech needed to not only diagnose the fault but to fix it as well. Use the contact information below or contact form to book your vehicle in for a diagnostic. We are happy to help.

A1-Diagnostics
64 Sloper Road
Leckwith,
Cardiff
CF11 8AB

Tel: (029 20) 220380
Fax: (029 20) 223172

Opening Times

Mon – Fri: 8:00am – 6:00pm

Email: info@a1-diagnostics.com