Q: How do you get access to replace the O2 sensors on a Audi A6 4.2 engine? There does not appear to be any room?

asked by on

The front O2 Sensors are difficult to extract and replace on a 4.2 L engine. The termination plug is easy to remove. Access to the muffler to extract the O2 sensor appears impossible. Clearly it is not possible from below, ie not possible from below the car.

My car has 100000 miles.
My car has an automatic transmission.

Hello. In order to remove the oxygen sensors, you will likely need an offset oxygen sensor wrench. An offset oxygen sensor wrench will be compact enough to fit into low clearances but still provide enough torque to break the sensors loose. Once the sensors are loosened, you can unscrew them by hand.

Reinstalling the new sensors would be a simple reverse of the removal procedure, start them by hand and then torque them down with the wrench. This procedure is usually done form above, through the engine bay, and may require the removal of some engine components, such as intake tubes or the coolant reservoir to properly access. If you cannot access the sensors even with an oxygen sensor wrench then another option would be to undo the manifolds in order to provide clearance to reach the sensors.

If you need help having this done, a certified technician from YourMechanic can come to your car’s location to replace the oxygen sensors for you.

Was this answer helpful?
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details
  1. Home
  2. Questions
  3. How do you get access to replace the O2 sensors on a Audi A6 4.2 engine? There does not appear to be any room?

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing

Get a quote

What others are asking

Q: How do I fix O2 sensor heater cylinders 1-6 circuit malfunction?

The oxygen sensor heater is integral to the sensor assembly itself. It is not separately serviceable. If the heater tests bad, the entire sensor is replaced as an assembly. In your case, P1193 refers to an oxygen sensor which is...

Q: Coolant is brown

The coolant level should be checked when the engine is cold. Typically you will check the level in the plastic recovery tank. If the level is low, or keeps dropping even after you top off the system, you might have...

Q: EPC light on an now I have no power, brake an battery light is flashing

You probably have a dead battery. The computer systems on your car will be prone to odd behaviors when the battery voltage gets low, so you may see lots of things that don't make sense. The battery could be dead...

Related articles

How Long Does a Distributor O Ring Last?
The distributor is part of the ignition system in your vehicle and its purpose is to route high voltage from the ignition coil to the spark plug. The spark plug then...
How Long Does a Heater Control Valve Last?
Keeping the right amount of coolant in a car is essential in keeping the engine at the right temperature. Failing to have the right amount of coolant or even bad elements...
Rules of the Road For Iowa Drivers
Driving on the roads requires knowledge of the rules, many of which are based on common sense and courtesy. However, even though you know the rules in...