Emmisions Q (not Jeeo) - JeepForum.com
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post #1 of 9 Old 02-18-2005, 04:52 PM Thread Starter
Broke Bogger
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Emmisions Q (not Jeeo)

Well my Mom failing emmisions today. Its on a 91 Chrysler New Yorker (my back up car) Anyway, since its Mopar, I figured maybe some of you tech gurus could help.

The sheet I have says NOx 1446 and HC 123 FAIL

Then is says standard NOx 879 and HC 117 I guess thats what its supposed to read or something, I dunno.

So, what do it have to do to fix it. Is it as simple as replacing the cat? There is no CE light on or anything, think maybe a sensor is messed up?

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post #2 of 9 Old 02-22-2005, 01:58 PM
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It is running *way* rich.

Check the air filter and do a tune up (if you have not done it already...)

Gleep! is a stock 98TJ 2.5L / 5spd with the soft top. Sylvania SilverStars [tm] and aftermarket headunit.

Oh yeah, I disabled the 'upshift' light...
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post #3 of 9 Old 02-22-2005, 04:21 PM
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Yeah whenever your HC's and Nox is high it usually indicates a rich running condition. As Gleep said, check the air filter, plugs, wires, cap,rotor and O2 sensor. Something is causing the engine not to properly burn all of the fuel in each cylinder.

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post #4 of 9 Old 02-22-2005, 04:32 PM Thread Starter
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I'll get right on that. I'm sure the thing hasn't had a tune up in years, we barely drive it anymore. So then the cat you think is still good? I guess thats good news. How come the check engine light isn't being triggered maybe its just burnt out, haha.
I'm pretty sure the air filter is good, I think I just changed it last oil job, but I'll pull the plugs and take a look. Thanks for all the help. I'll be back when I see whats up with em

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post #5 of 9 Old 02-27-2005, 11:37 AM Thread Starter
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Back again. Yea the air filter wasn't the cleanest, but it wasn't to too bad. I replaced it anyway. I got 3 of the sparks out, no problem. They were shot, caked with a white nastyness yeah, pretty bad. But, the rears are like impossible to get too. Is there an easy way of doing this? I'm not used to working on a V 6 like this. Why do they make a simple tune up so hard to do

Lastly, I remember hearing little tricks about passing emmisions. Something like adding a bottle of alcohol, and using the best gas, stuff like that. Will that help in my case??? and is that like rubbing alcohol you buy at the drug store or something special? I'm trying to get any thing I can to make this work.

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post #6 of 9 Old 02-27-2005, 12:45 PM
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High NOx readings are a clear sign of performance issues somewhere in the system. The question is, where?

The potential causes of non-compliant NOx readings are:

Misfire condition
Malfunctioning or improperly adjusted EGR valve
Failed oxygen sensor
Leak in exhaust tubing upstream of converter
Excessive carbon deposits in combustion chamber
Improper spark advance
Blocked coolant passage
Overly lean air-fuel mixture
Damaged cold air duct
Corroded or damaged engine sensor electrical connections

While a failed catalytic could contribute to high NOx readings, the failure in itself most likely would have been caused by some other upstream problem.
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post #7 of 9 Old 08-14-2005, 12:05 PM Thread Starter
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sorry to bring up an old thread, but I'm almost there. I changed the sparks and serp belt and got a reinspection. The HC passed this time, but the NOx is still 200 to high, but at least it came down some.

I got a new EGR, but I have no idea where it goes. I looked under there for a good while and found nothin that looked like the new one. Where are they typically found???

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post #8 of 9 Old 08-21-2005, 11:49 PM
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This trick will make almost any car pass an emissions test. Change your oil then go straight to the testing station. make sure the engine is warmed up to operating temp. Brand new oil will absorb almost 100% of your emissions for about 300-500 miles. I have never had one fail the test. One jeep i owned had the catalytic converter removed and it still passed....hope this helps you

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post #9 of 9 Old 08-22-2005, 07:25 AM Thread Starter
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I seafoamed the crap out of it the other night, man that was so funny. The hole block was like a smoke screen on a beach invasion or something, hahaha. Anyway, I can deffinatly tell that the smell of the exhaust has changed for the better, so hopefully thats enough to pass it, but to be safe, I'll change the oil too, thanks.

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