Loosen or take out the bolts that secure the engine cover in place and take off the cover. Find the PCV valve at the valve cover and disconnected the hose then removed the PCV valve since the clamp is fixed using plier and the hose can be pulled off. Replace the O-ring each time the PCV valve assembly is pulled out. connect the hose back to the valve, and with the engine running at the normal speed on normal temperature, block the end part of the valve with your finger. Hose and valve must have no vacuum If there is no vacuum at the valve, it is good to check if a hose or the valve is plugged; in this case, the faulty hoses must be replaced with the suitable ones if they have worn out. Before buying a new PCV valve, make sure that it will fit the specific make and size of your vehicle and your car's engine, comparing the old and new valves they should be almost same. Again, removal is done in an opposite sequence to installation.