I do diasnostic test and the answer is low flow detected, have 4 probable cause; EGR passages bloked. EGR pintle stuck closed EGR volume control valve open or shorted EGR temperature sensor error. I need diagram to faund all those places to fix or check wich one is the problem. thanks.
service eng. light on 1998 Nissan Sentra
by torito23 in Beaverton, OR on March 18, 2009
ANSWER by dandd , March 19, 2009
First thing to do is to let the car idle and fully warm up and then use a vacuum pump and apply about 5-7 inches of vacuum to the valve. The car should die IMMEDIATELY, not stumble, DIE! If not, make sure the valve is raising by feeling the pintle with your finger ( be careful, it will be HOT ) if the pintle raises and the car does not die, then the passages are clogged. Clean them out. If the pintle does not raise, the valve is defective. Then if this test is ok, attach a vacuum gauge to the line going to the valve and raise the rpm to 2000-2500 and see if there is at least 4-6 inches of vacuum applied. If not, then there is a vacuum source problem. If there is vacuum, then remove the temp sensor and see if it has carbon on it. If so, clean it off until it gleams. Use a GENTLE wire brush and some carb cleaner. This should get you going. I do Emissions work and I just did 3 Nissans this week alone. I find that the Nissan Diagnostic Flow charts to be a bit obtuse.