failed emissions
- Thread starter alky350
- Start date
joe_peters
NAXJA Forum User
- Location
- Grants Pass, OryGun
Date of last tuneup?
Date last changed fuel cap?
Date last changed fuel cap?
SFW516
NAXJA Forum User
- Location
- Anaheim, CA
From your numbers it looks like your running pretty rich. If you posted oxygen numbers it would help clarify. From what I remember of the smog class I took your running very rich. One handy tool is to plug your numbers into a Lambda calculator. It will calculate exactly how your doing. Handy tool. There is one on this site - http://www.smogsite.com/calculators.html#lambda
It looks like you got a bit of a Nox problem. So combustion temps are too high. Could be overheating or carbon build up in cylinder. And if you have an EGR valve you should check that. Not sure if your Jeep has one though, I know my 90 does and it really keeps the Nox way down.
Just some thoughts I had.
It looks like you got a bit of a Nox problem. So combustion temps are too high. Could be overheating or carbon build up in cylinder. And if you have an EGR valve you should check that. Not sure if your Jeep has one though, I know my 90 does and it really keeps the Nox way down.
Just some thoughts I had.
Last edited:
- Location
- Southern Maryland
I'm gonna say the cat is busted. A working cat splits NOX into plain old nitrogen and oxygen, combines some of the oxygen with CO to produce CO2, and uses the rest to dilute the hydrocarbons. Yours doesn't seem to be doing anything. Did you land on a stump with it? Was the cat cold when you tested?
