Engine Performance problem
1996 Nissan Sentra 4 cyl Front Wheel Drive Automatic 100000 miles
I got some performance issues with my car. The first thing it happen when I hear a noise at my engine, I didn't know at that time what happen, but I found later that a hose around the EGR valve exploded. My car was still driveable, but the light " check engine" turned ON. I try to pass my fumes test and I didn't pass, the problem the machine read from my car computer was:
P0401 - EGR Valve FLOW.
This is when I found and changed the exploded hose and after that I pass the fumes test. But shortly after the lproblem came back, and the " check engine" light came back on, and the engine dont run that well, especially when it is hot outside.
I foundthat the code 401 means:
Exhaust Gas Recirculation Flow Insufficient Detected.
How can I fix this, changing the EGR VALVE will be enough?
Changing the EGR would solve the problem if it is the source of the problem.
However you should also check the electricals to ensure that there is nothing wrong there.
June, 21, 2008 AT 10:13 PM
This EGR valve is part of a system that includes the valve itself, a vacuum solenoid, a temperature sensor and a backpressure transducer valve. The valve itself is easy to check; just apply vacuum (with a vacuum pump or even with your mouth) to the hose that goes to the top of the valve while you feel underneath it to see if the diaphram rod moves. An insuffient flow, however, is most likely caused by deposits gumming up the valve or intake manifold passage where it bolts. If they're not blocked, suspect the backpressure valve.