Quote Originally Posted by jfman
And if you dont know what your talking about, dont post, anybody can say "put a new cat and 02 sensor on it"


Car : bone stock 1993 300z

It failed the NOx ppm reading.... What can be the cause of that.


the reading was 2321 and the limit is 907

It passed the HC-ppm and CO% with flying colors.

I want to know what this means..
I SEE U EDITIED UR POST. IM ASSUMING U THINK I WAS BSING U BY THE WAY I POSTED BUT THE TRUTH IS IM PROLLY RIGHT. UR CATS ARE A SOURCE OF BACK PRESSURE. IF THEY GO BAD AND THE ACTIVE MATERIAL IN THEM COM OUT IT WILL TO AN EXTENT CAUSE UR EXHAUST TO FLOW ALOT BETTER CAUSING UR CYLINDERS TO GO LEANER WHICH INCREASES UR CYLINDER TEMP. DO U HAVE NEW CATS ON THE CAR?