I failed my emissions on a 95 accord lx, the reason was NOx was too high

25/25 NOx Allowed 945 Mines 1323
50/15 NOx Allowed 1045 Mines 1307

i was told the cat is bad to i replaced the cat with a walker cat, cleaned the egr ports, seafoam the crankcase, gas tank, oil, did an oil change drove 300 miles and went to retest and got this:

25/25 NOx Allowed 945 test 1470
50/15 NOx Allowed 1045 test 1535

it failed again with worse number? what can be wrong? thanks

 

Problem is common w/ Accords and is usually caused by blocked EGR ports and passages. There is a DIY link to repair procedures to clean the EGR system.

good luck

 

i cleaned the egr system just like the dyi said

 

check your lambda sensors and cat

 

This problem is usually caused by lack of EGR flow. I would check EGR valve (is vacuum available to open the valve); EGR-EGR manifold passage clean/open; EGR manifold ports open; and underlying ports from EGR manifold into intake manifold are open.

good luck

 

could it be the o2 sensor? when i get drive the car in the morning it shows the check engine light for code 9 CYG Sensor but after a while the light goes away