What is the Exhaust Pressure Control Valve?
Diesel vehicles are furnished with systems that reduce air pollution and the emissions coming from the tailpipe. For diesel engines, especially furnished with a turbo, a system called exhaust gas recirculation is used to bring exhaust with unburned fuel back through the combustion chamber to burn even more thoroughly. This system’s flow is regulated by an exhaust pressure control valve, which senses changes in the exhaust pressure and controls the vacuum through the EGR valve.
It is mounted directly onto the body of the turbo. It limits the amount of ‘dirty’ air that is circulated back through the engine under certain throttle positions and conditions. If the exhaust pressure control valve is not functioning appropriately, the engine light can come on. The engine will run rough as an improper amount of air is metered into the engine, and you can see evidence of large amounts of unburned fuel coming out the tailpipe in the form of black smoke or soot.
Bear in mind:
The exhaust pressure control valve is difficult to analyze without specialized equipment and should only be done by one of your expert mechanics.
All exhaust and emissions parts like the exhaust pressure control valve are needed to be in functioning order in state smog or emissions tests.
How to Fix:
The vehicle is held on jack stands
The faulty exhaust pressure control valve is removed
The new exhaust pressure control valve is fitted
The vehicle is removed from the jack stands
The vehicle is road tested to check exhaust system
The exhaust pressure control valve should last the lifetime of your vehicle. If your engine light comes on and you experience a loss of engine power, you may need one of your expert technicians to change the exhaust pressure control valve.
Common signs indicating you may need to change the Exhaust Pressure Control Valve:
Check Engine light is on
Noticeable loss of power
Excessive soot from the exhaust
Importance of this service:
An unrepaired exhaust pressure control valve can cause further, more expensive repairs to the turbo or exhaust gas recirculation system. As it radically affects your engine’s performance, the exhaust pressure control valve should be changed as soon as signs are present and the condition has been properly analyzed.