How do I fix my engine running too rich?

Car Running Rich: How To FixCheck The Air Duct’s Flap. The flap inside the air duct is an actuator that serves as choke. Vacuum Lines And Hoses. Loosely connected or leaked vacuum lines and hoses can cause a vehicle to run rich. Clean The Mass Airflow Sensor. The Oxygen Sensor. Change the spark plugs.

Can a vacuum leak cause a rich condition?

A vacuum leak can cause a rich condition and raggedy running. If the leak is medium, the ECU will detect something is wrong and run in one of its mapped safety modes. Most likely will not show a CEL.

What are signs of a vacuum leak?

Symptoms of a vacuum leak include the Check Engine light, rough idle, stalling and a hissing sound coming from the engine bay. The engine may run well at higher RPMs, but surges, runs rough and struggles to maintain stable RPMs at idle. Often, the engine stalls when stopping.

What should Stft be at idle?

Ideally, the STFT and LTFT should be within a few percentage points of zero when the engine is idling or being held at a steady RPM. Good LTFT values should be as close to zero as possible, though they can range from 5 to 8 percent depending on the condition of the engine.

Is it safe to drive with a vacuum leak?

Driving with a vacuum leak should not be done because it causes a loss of power to your engine. This can be unsafe while driving down the road, especially if the leak increases as you are driving.