I need help passing smog.
- Thread starter poomero
- Start date
- Location
- Seattle, WA
Post up the numbers from your smog paperwork. What did you fail for?
JeepCherokeeGuy99
NAXJA Forum User
- Location
- New Bern, NC
need the basics. year, motor, etc.
Did you pass the visual inspection and only fail the functional inspection? o2 Sensors could be trash. Or is your jeep misfiring at all? CEL on?
Did you pass the visual inspection and only fail the functional inspection? o2 Sensors could be trash. Or is your jeep misfiring at all? CEL on?
JeepCherokeeGuy99
NAXJA Forum User
- Location
- New Bern, NC
Did they list any functional parts that didn't pass? For example, the EGR
Last edited:
blondejoncherokee
NAXJA Member
- Location
- sacramento
pretty much what lodi jim said
cap.rotor.plugs.wires.o2 sensor.clean grounds. clean throttle body. change oil. air and fuel filter prob wont hurt.
test EGR valve . check for vacuum leaks and exhaust manifold leaks.
visually inspect inside of cat as well. if its bad replace it.
make sure the 4.0 has been running for at least 15-30 mins before you take it in too (get the cat nice and warm) . how old or new is the TPS?
ive heard guys on here say that when all of your numbers are very high that its most likely the cat.
cap.rotor.plugs.wires.o2 sensor.clean grounds. clean throttle body. change oil. air and fuel filter prob wont hurt.
test EGR valve . check for vacuum leaks and exhaust manifold leaks.
visually inspect inside of cat as well. if its bad replace it.
make sure the 4.0 has been running for at least 15-30 mins before you take it in too (get the cat nice and warm) . how old or new is the TPS?
ive heard guys on here say that when all of your numbers are very high that its most likely the cat.
Hoooper
NAXJA Forum User
- Location
- Hayward, CA
^^^ i agree with this (cat worn out). cats dont last forever and they do wear out. when they do your readings all get high. When youve got high HC and NOx, its roughly saying that youre running too rich and too lean. obviously, you arent running both so...HCs are unburnt fuel, and NOx is the result of a lean mixture causing high combustion temps. High CO, on the other hand, is typically due to incomplete combustion. From what ive seen, high CO is usually caused by needing a tune up or needing to replace O2s.
JeepCherokeeGuy99
NAXJA Forum User
- Location
- New Bern, NC
Cat could glow red from heat build up and/or a rattling noise. Regardless, id replace the cat and o2 sensors
JeepCherokeeGuy99
NAXJA Forum User
- Location
- New Bern, NC
Nope, that would be illegal and
does not support illegal activities. There's government grants that will give you $500 to repair emission related issues if you qualify.
JeepCherokeeGuy99
NAXJA Forum User
- Location
- New Bern, NC
Yes it could, but the same could be said about the o2 sensors...
JeepCherokeeGuy99
NAXJA Forum User
- Location
- New Bern, NC
Exactly, and you'd have to deal with the bad gas mileage another 2 years lol. The form you need to fill out is a CAP application. The info can be found on the back of your registration renewl notice.
JeepCherokeeGuy99
NAXJA Forum User
- Location
- New Bern, NC
Anytime
blondejoncherokee
NAXJA Member
- Location
- sacramento
this is making me think some of my bad gas mileage could bea bad cat on my Xj since every sensor on my junk is new and my last smog readings all passed but they were all very high (just below failing) which was starting to make me think that maybe my cat is going...
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