The most common causes of insufficient EGR flow are carbon build up in the EGR valve and a malfunctioning EGR valve. The EGR valve, or the exhaust gas recirculation valve, reroutes exhaust gas back into the intake manifold where it is drawn into the engine cylinders. Without proper EGR flow, a car will not pass an emissions test because insufficient flow causes a high saturation of noxious gas.Know More
The easiest way to determine what is causing insufficient EGR flow is to take the car to a mechanic. When a diagnostic test is run, certain codes indicate that the EGR valve needs to be replaced. If no codes result from the diagnostic test, check to see if there is excessive carbon build up in the valve. To fix this problem, take a speedometer cord and fray the ends. Insert the frayed ends into the valve. The ends of the cord attract and remove carbon from the valve.
Another common cause of restricted EGR flow is a blockage in the tubes leading from the EGR valve to the intake manifold. When a line is blocked, the tubing becomes distorted and enlarged. It is important to inspect the lines for cracks or breaks because this also causes insufficient EGR flow.Learn more about Car Parts & Maintenance
An EGR valve helps to improve the performance and economy of a vehicle while reducing emissions by directing exhaust gases back into the cylinders of the vehicle for a second burn. The valve reduces nitrous oxide emissions and directs the warmer exhaust back into the engine, reducing the amount of work required by the fuel-and-air mix in maintaining the engine at operating temperature.Full Answer >
To replace an exhaust gas recirculation valve, the emissions system should be tested, the vacuum line removed and the unit replaced. The unit is generally mounted on or near the intake manifold of the vehicle.Full Answer >
A flow totalizer measures the amount of liquid or gas that flows through a pipe. Flow totalizers come in a variety of styles, and they are used in a wide variety of applications. By recording the results of the totalizer and dividing the amount over a quantity of time, the user can determine the average flow rate of the pipe.Full Answer >
To clean a mass airflow sensor, remove it from the vehicle, submerge it in a plastic freezer bag filled with rubbing alcohol and shake the bag until the sensor is clean. This 30-minute procedure requires a flat head screwdriver, a plastic freezer bag, rubbing alcohol, latex gloves and a towel.Full Answer >