Q: Audi A4 B8 chasis 2.0 tfsi Running rich

asked by on November 29, 2016

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.

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