
Originally Posted by
DallasBill
OK... I had a full Inspection II done just last Sept and the oil is clean. Yet, on inspection this morning (fully warm, freeway speeds for 1/2 hour beforehand) the low speed HC is 197 (pass is <117) and the low speed NOx is 1364 (pass is <879)!
High speed numbers were fine, but even those HC & NOx numbers were double last year's pass results -- and I had gone 1.5 yrs since the last tuneup back then! WTF?
Could this be O2 sensor(s), or ??? I also get the cold morning gas smell (but not today), so could that have something to do with it? (I know I need to get those fuel rail hoses checked).
I had very similar numbers as you on my Calif. emissions test.
The Catalytic converter that was installed by the PO, before I bought the car was defective (broke apart internally).
New Cat fixed it.
Do you get a sulfur smell too ? That would indicate a bad Cat.
If you are getting a raw fuel smell from the exhaust, that could fry the cat as well.
Best to get that fixed before a new Cat install, so it doesnt damage it again.
1991 525i M50 5 Sp.
N.California
America is all about speed. Hot, nasty, badass speed. -Eleanor Roosevelt