I just went to get my car smoged and it failed at 15mph but it passed at 25mph. The reason I failed is because at 15mph the max NOx levels are 487 and my car did 691.

At 25mph the max NOx is 774 and my car did 594.

I am wondering what I can do from home to lower my NOx levels. I am already going to clean my EGR valve. Is there anything else you can think of that I can do from home.


Thanks
-Nick

 

Forgot to mention that my car is a 96 civic EX

 

maybe your catalytic converter needs replaced depending on if it was ever done. Youre car is 12 yrs old so it mgiht be tiem if it wasnt done