Q: Audi A4 B8 chasis 2.0 tfsi Running rich

asked by on

Getting rich at idle and off idle codes and air intake leak. Seems to be worse when out side temp is over 90°. It surges and trailer hitches as I drive. When I first started it after sitting over night or a few hours I have to let it idle for a few minutes n or it will die when I put it in drive. It misfires on all 4 cylinders randomnly, I monitor the car with an obd2 scanner as I drive but I can't seem to figure out what is causing this. I have tried cleaning and eventually replacing the m.a.f, pcv, spark plugs, air filter, oxygen sensors, checkEd for a leak but found nothing. I still haven't tried a smoke test for a leak but I am hoping someone can steer me in the right direction.

My car has 98000 miles.
My car has an automatic transmission.

There are just a few things that will make your car run rich, you have already replaced the MAF, so that leaves the Coolant temp sensor,(CTS) the Throttle position sensor(TPS) and the fuel pressure. The temp sensor and the throttle sensor will show up on the scanner in the live data stream while you drive. If the temp sensor shows a lower than actual temperature, or the TPS shows a larger than actual throttle opening, either one of those will tell the ECU there is a greater demand for fuel. If the fuel pressure is too high, that may not show up on the data stream but it will make your car run too rich. If you still can’t sort this out. You can contact Your Mechanic to have a technician come to your home or office to check out your car and tell you what needs to be done.

Was this answer helpful?

Need advice from certified mechanic? Get help now!

Over 1,000 mechanics are ready to answer your question.
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. Audi A4 B8 chasis 2.0 tfsi Running rich

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: Vehicle serviced and the dash still says needing serviced.

Question sent to CS for the concern of the service engine message coming back on after having the vehicle serviced and the cost to have the vehicle checked out.

Q: My rear left turn signal will not work and I have replaced the bulb and checked the fuse.

Hey there. The most likely problem is the bulb holder / socket itself. It may look fine but probably has a crack or break internally. Also possible (but rare) is the circuit board within the tail lamp housing itself. I...

Q: Faulty door locks

Hello, and thank you for writing in. Getting a second opinion is always a good idea. Your vehicle has the option to open just the driver's door, or to open all of the doors. Typically you click the key fob...

Related articles

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...
P0240 OBD-II Trouble Code: Turbocharger Boost Sensor B Circuit Range/Performance
P0240 code definition Turbocharger Boost Sensor B Circuit Range/Performance What the P0240 code means P0240 is an OBD-II generic code triggered when the Engine Control Module (ECM) detects the intake boost...
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...