Join the community and post your question. Use our Ask-A-Tech for free now! ASE experts standing by.

Forum > Failed Smog Test > Question

1997 Honda Del Sol failed smog inspection for high NOx.

My 1997 Honda Del Sol has 140,000 miles on it. When I attempted to smog check the vehicle it failed the NO at 15 mph (487 max 537 measured) and passed at 25mph (774 max 663 measured)i replaced cap/rotor/plugs and wires, exh manifold, both 02 sensors and magnaflow 46628 cat converter. now it failed as a gross polluter wit NO at 15mph (2298 measured) and at 25mph (2140 measured). vehicle does not have an egr valve or a maf sensor. I am at a complete loss. Any suggestions?
Answer:

You want to look at your Honda Del Sol's fuel feedback system. Your Honda Del Sol may very well be suffering from a lean fuel condition. Lean fuel conditions can cause high NOx smog check failures. Your Honda does not have a mass air flow sensor, but it uses the map (Manifold Absolute Pressure) sensor along with the throttle position sensor and intake air temperature sensor to tell the ECU how much air is entering the intake manifold. The oxygen sensor data is only one part of the air/fuel mixture calculation. The rest of the emission sensors should be inspected as well. In this specific case since the NO increased after replacing the Oxygen Sensor we highly recommend ensuring the repair was done correctly, using the correct replacement parts. posted by SmogTips Support

Related questions and answers you might find useful:

How Do I Get a Smog Check Waiver? by Margaret

Do I Need a Smog Check This Year? by Joy

Mini Cooper DMV Registration Due in 5 Day Won't Pass Smog by anne

2001 Jeep Grand Cherokee Laredo with K&N Air Filter by David

1995 BMW M3 Gross Polluter High HC & NO @ 15MPH by Jared

View SmogTips.com in: Desktop / Mobile