Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum - View Single Post - HiGH NOx smog test need any help to pass!!

modulation · 10-11-2009, 08:52 PM

I'd bet you had a pre-cat exhaust leak.
I had similar problems (really high nox, low hydrocarbons.)

Turned out to be a exhaust leak right before my cat.

10-11-2009, 08:52 PM	#47
modulation Zilvia Member Join Date: Apr 2008 Location: San Jose Posts: 191 Trader Rating: (0)	I'd bet you had a pre-cat exhaust leak. I had similar problems (really high nox, low hydrocarbons.) Turned out to be a exhaust leak right before my cat.