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Forum > Failed Smog Test > Question

1995 Nissan Pathfinder failed smog check for high NO. What's wrong?

The NO reading at the smog test center was high(636) Every other reading passed and the engine light is not on after installing a new catalytic convertor. As stated before I failed because of a high NO reading. A new oxygen sensor was also installed as well as a new fuel filter. A new back pressure transducer was installed. The EGR was tested and is functioning. I started checking the computer for error codes and there are none but in Mode 5 I am coming up with a steady red light blink that indicates a bad crank angle sensor. What is this all about?
Answer:

We'd recommend a fuel feedback test on your Nissan Pathfinder to make sure the new oxygen sensor is feeding information to the emission computer. Oxygen sensor information must be passed to the computer, the computer needs to send the correct signal to the fuel injectors, and the injectors have to allow the right amount of fuel to the combustion chambers. You need to ensure this system is working properly. If all is good with the fuel feedback test, then move on to the EGR system and ensure the EGR passages are all open, both on the exhaust side and the intake manifold side. posted by SmogTips Support

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