Will not stay running.

ANSWER : Hello. From the symptoms you describe, it would appear that your vehicle is having issues with the oxygen sensors. P0172 is the code for bank 1 being too rich. This can be caused by a wide variety of issues. The other two codes are for the sensors on bank 2, having excessively high voltage.

This may be due to the rich condition, faulty oxygen sensors, or faulty wiring. The black smoke and soot is a result of excessive fuel that is not being properly burned, and exiting the tailpipe as smoke. A few common causes for these symptoms are a bad fuel pump, fuel pressure regulator, or engine management sensor. As engine management systems can sometimes be difficult to diagnose, I would recommend having the rough idling issue inspected by a professional technician.

ANSWER : Hey there. This can be caused by a number of things such as low coolant levels, a faulty thermostat, or a failing coolant fan switch.

As you may know, the coolant fan switch helps to maintain the proper coolant temperature by turning on and off at specific temperature thresholds. When this switch is not working properly, this can cause the fans to come on intermittently, all the time or sometimes not at all.

In your case, if they are on continuously, this may not allow the car to reach normal operating temperature as you have noticed. When this happens, you will notice a temperature spike and drop occasionally as the fan comes on and off. I would suggest having an expert from YourMechanic come to your home to diagnose your cooling system and pinpoint any needed repairs.

ANSWER : Hi there. Check the spark plugs and see if they are sparking. Get a code reader and check for any codes that could be stored in the computer as the check engine light is on. The code will give you a starting point for diagnostics. I recommend replacing the spark plugs and plug wires if they are more than 80,000 miles or 5 years old. If the spark plugs are working good, then check the fuel injectors and see if they are working by removing the harness to each injector one at a time. If the engine stumbles more than normal, then the injector is working. I recommend seeking out a professional, such as one from Your Mechanic, to help you diagnose a misfire if you need further assistance.

ANSWER : This may be a sign of a faulty MAP sensor as the vehicle responds adversely to a load put on the motor (i.e. putting it in gear, turning on AC or engaging the brakes). The Manifold Absolute Pressure (MAP) sensor senses engine load and generates a signal that is proportional to the amount of vacuum in the intake manifold. The engine computer then uses this information to adjust ignition timing and fuel enrichment. When the engine is working hard, intake vacuum drops as the throttle opens wide. The engine takes in more air, which requires more fuel to keep the air/fuel ratio in balance. When the computer reads a heavy load signal from the MAP sensor, it adjusts the fuel mixture to slightly more rich than normal so the engine can produce more power. The computer will then retard (back off) ignition timing slightly to prevent detonation that can damage the engine and decrease performance. This may also be caused by other closely related components such as a dirty or failing mass air-flow sensor, a faulty throttle position sensor or potentially a vacuum leak. I would recommend having an expert from YourMechanic come to your location to diagnose and inspect your vehicle.

ANSWER : Hi there. One of the key ingredients needed for an engine to run is fuel. If the fuel pump is disconnected the engine may start briefly with whatever fuel is left in the injectors or rails that drips into the intake manifold. If your vehicle continues to exhibit this concern after reconnecting the fuel pump I suggest having a qualified technician perform an inspection to avoid replacing unnecessary parts. Your Mechanic has several available technicians that can assist you with a car starts and stalls inspection.

ANSWER : It sounds like you may have a dirty or failing idle air control valve. The idle air control valve monitors the air intake as it is mixed with fuel prior to being injected into the engine at low speeds and at idle. This valve is controlled by the vehicle’s computer and will adjust idle speed based upon other measurements such as engine temperature, intake air temperature and electrical system load or voltage. This is also an important function when starting the motor as it allows the motor to run and idle on it’s own once the motor fires. When you accelerate, the engine RPM increases, and as you let off the gas, the RPM slowly returns to the normal idling speed with the help of the idle air control valve making the transition from a higher RPM back down to idle speed while adjusting the air/fuel ratio constantly to allow this to happen smoothly. When the engine RPM drops below the normal range of about ~800 RPM, this often times will cause the engine to stall indicating a dirty or faulty idle air control valve. I would recommend having an expert from YourMechanic come to your location to diagnose and inspect your vehicle.

ANSWER : The fuel pump in the fuel tank is designed to have low pressure and high volume to feed the front fuel pump the right amount fuel. The front fuel pump supplies the engine with high pressure to the engine.

When you do not hear the pump run then the fuel pump is bad and should be replaced along with the relay. You should not have to replace the in tank pump if it is running. I’d suggest replacing the fuel filter as well.

I’d suggest getting this inspected by a qualified technician, such as one from YourMechanic, to diagnose your stalling issue and make the necessary repairs.

ANSWER : Hello – your symptoms suggest a failing injector . It appears to be leaking when it’s plugged in, as well as noisy. Check for problem codes relating to a rich mixture,, although it’s possible that the oxygen sensors for that bank of cylinders is leaning out the other 3 on that side. This would create rough running for sure. That would explain the popping (probably backfiring or misfiring at least on the lean cylinders). I recommend a misfiring inspection performed by a mobile, professional mechanic, such as one from YourMechanic, who will come to your location, diagnose this problem, and give you an accurate assessment of damage and cost estimate for repairs.