Failed Emissions, NJ

old_whitey88 · Oct 26, 2007

Good morning Gents,
I have been having this on-going problem with my poor old XJ. Twice now already i failed (NJ inspection) for emissions. my NoX is well above average.

First thing i changed was my EGR valve. nothing happened. i brought it back, and my Nox is actually HIGHER.

i've had people tell me that i need to change my catalitic converter. is that the only thing that could be wrong? i'm pretty stumped.

thanks for any suggestions,
Leslie

ParadiseXJ · Oct 26, 2007

Most common

IMHO)
O2 sensor (how old-miles)
Cat (rattling?)
Vacuum lines (to from valve cover, manifold, air box) cracked, cut, missing?
Gas cap old? corroded, missing? Replace every couple years
Clogged CCV (PVC) pop it off and run some compressed air through it.

When is the last time you replaced plugs, wires, cap etc (tune-up)

How does it run?

pabloconrad · Oct 26, 2007

My dad had the same problem. He kept taking it a mechanic and it kept failing.

Then my dad put on a new Cat and it passed with flying colors.

How old is the jeep?

xj4fun · Oct 26, 2007

If I was only given one choice, I'd opt for a failed cat. However, the other suggestions are cheaper, quick changes. So you may want to address them first.

cal · Oct 26, 2007

I'm another vote for 02 sensor. Its $60 well spent, it clears up the nox and can help with mpg.

87manche · Oct 26, 2007

tried de carboning your intake.

seafoam the motor, the byproduct of the EGR system in the renix rigs is a ton of carbon buildup. Too much carbon buildup in the combustion chambers would raise the combustion ratio, causeing the combustion chamber temp to be high, causing high NoX

I'd try that, and I'd take a good hard look at the cat.

FWIW, both of my 87's ran much better after they sucked some seafoam in through the brake booster hose, it's a cheap backyard thing to do as well.
Your neighbors will hate you though.

BB1980 · Oct 27, 2007

Move to SC. We don't care bout no darn O Zone layer.. ...

We do not have emissions testing....

old_whitey88 · Oct 29, 2007

ParadiseXJ said:
Most commonIMHO)
O2 sensor (how old-miles)
Cat (rattling?)
Vacuum lines (to from valve cover, manifold, air box) cracked, cut, missing?
Gas cap old? corroded, missing? Replace every couple years
Clogged CCV (PVC) pop it off and run some compressed air through it.

When is the last time you replaced plugs, wires, cap etc (tune-up)

How does it run?

Well my 02 senser was just changed in the summer so i know thats fine. i have platinum plugs, new wires (again changed in the summer) I didnt think of the vac lines so that may have some merit. gas cap seems fine. As for running, i stall while in drive and sitting at a light. i tend to bog down, then leap while in third. i have no clue what the hell thats all about but its regular--but infrequent.

i just figure it has to do with whatever is wrong.

thanks for the ideas.

--Leslie

old_whitey88 · Oct 29, 2007

pabloconrad said:
My dad had the same problem. He kept taking it a mechanic and it kept failing.

Then my dad put on a new Cat and it passed with flying colors.

How old is the jeep?

88.

old_whitey88 · Oct 29, 2007

BB1980 said:
Move to SC. We don't care bout no darn O Zone layer.. ...

We do not have emissions testing....

hhhaaaa haaa! i wish man. farthest south i've ever gone was Virginia. well mexico doesnt count. i was young and in college.

old_whitey88 · Oct 29, 2007

87manche said:
tried de carboning your intake.

seafoam the motor, the byproduct of the EGR system in the renix rigs is a ton of carbon buildup. Too much carbon buildup in the combustion chambers would raise the combustion ratio, causeing the combustion chamber temp to be high, causing high NoX

I'd try that, and I'd take a good hard look at the cat.

FWIW, both of my 87's ran much better after they sucked some seafoam in through the brake booster hose, it's a cheap backyard thing to do as well.
Your neighbors will hate you though.

Egon usually helps me with my issues, but the two of us have been very busy. i'll ask him about that seafoam stuff. see what thats all about. We recently did a carbon clean out though, prob end of august, but i still failed. -sighs-

--Leslie

87manche · Oct 29, 2007

old_whitey88 said:
Egon usually helps me with my issues, but the two of us have been very busy. i'll ask him about that seafoam stuff. see what thats all about. We recently did a carbon clean out though, prob end of august, but i still failed. -sighs-

--Leslie

if you've done a carbon cleaner then te seafoam probably won't help.

Since you've got driveability issues then I'd really look at the vacuum lines, and then start tackling the sensors.

Ones I'd start with are the TPS and the MAP sensor, both of those have direct input on how much fuel the motor gets.

Failed Emissions, NJ

old_whitey88

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ParadiseXJ

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pabloconrad

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xj4fun

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cal

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87manche

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BB1980

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old_whitey88

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old_whitey88

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old_whitey88

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