I am a gross polluter!!

AirForce_XJ

NAXJA Forum User
Failed smog today, well, half of smog. Passed at 25 MPH failed at 15. By almost 3 times the allowable limit. New filter is in, have new pugs, gonna check all my vacuam lines and the exhaust. Anything else I should take a look at?:repair:
 
Catalytic converter maybe?
 
Sounds like converter.Have a new one installed and drive the Jeep for at least 20 miles to "cure" the converter. Install new O2 sensor. Have Jeep good and warmed up before going back for re-test.
 
i figured it would be nox..time for a cat buddy, have them do a full exhaust inspection while there under there. good luck with the SMOG.
 
also high combustion temps will cause it. at first i tried a new cat that didnt work and then a bigger cat that didnt change anything either. to get it to pass i had to go 3 steps colder on the plugs, new cap, rotor and added acetone to the gas. it dropped from 1900 down to 649 on the nox.
 
Running hot will definetly lead to more nox, and 100% of the egrs job is to lower nox emissions by lowering combustion temps. its funny that the smog guy didnt notice your disconnected egr, thats suposed to be an automatic fail :D

edit- I had the same issue and I recomend doing what the poster beforw me said.
 
Talk about the 'ol shotgun diagnosis. Everyone always says to put a cat and an o2 on it. Well....maybe. The big thing is why did the cat fail? What year is your rig? You said it has EGR so that is a Renix era rig.

High NOx can be cause by many things. Your EGR valve being disconnected or inoperative will cause you to fail big time. Also an exhaust leak before the cat will do the same. High engine temps or a lean air/fuel mixture also contribute to high NOx. If your rig is running at a normal temp I wouldn't worry about running hot just yet. Excessive carbon build-up in the combustion chamber will cause high NOx. Just putting a new cat on will probably get you to pass, but I have no doubt you will need another cat in 2 years to pass again.

What to do first? Grab your smog check report and head over to this website: http://www.smogsite.com/calculators.html#lambda You might have to scroll down the page a bit to find the Lambda calculator. Start plugging in the info about your emission levels and percentages. Be sure to input them all exactly as shown on the smog check report. Click the calculate Lambda button and check the results by looking at the colored bar right below the calculate button. Now what this does is tell you if you vehicle is running correctly, not too rich or too lean. A lambda reading of 1.0 is considered perfect. As long as your reading is in the green section then you probably have a bad cat. If the reading is in any other color than green then you have to figure out why the engine is running rich or lean before doing any other repairs. This website is easy to use and will tell you pretty definitively what is going on in your engine. If the engine is running too rich or too lean, a cat isn't going to fix your problem. You may still need a cat, but at least you won't kill your cat and have to replace it again to pass smog next year. Oh, that's the other fun thing about being a gross polluter, you have to get your rig smogged every year for the next 3 or 4 years.

Start there, and please report back what the calculator said. If you want to post up your numbers and I can run them to see what I think.
 
ok i got a question for you Bryan. You said that if you have an exhaust leak it will cause you to fail? Well i have an 87 and when i bought it the exhaust manifold was cracked. i had about a 1/4 to 1/2 an inch of gap on the rear two pipes. I didnt realize it until after i smoged it 2 years ago and it passed with flying colors...
 
ok i got a question for you Bryan. You said that if you have an exhaust leak it will cause you to fail? Well i have an 87 and when i bought it the exhaust manifold was cracked. i had about a 1/4 to 1/2 an inch of gap on the rear two pipes. I didnt realize it until after i smoged it 2 years ago and it passed with flying colors...


Just because you passed doesn't mean your emission levels weren't higher than normal.
 
Talk about the 'ol shotgun diagnosis. Everyone always says to put a cat and an o2 on it. Well....maybe. The big thing is why did the cat fail? What year is your rig? You said it has EGR so that is a Renix era rig.

High NOx can be cause by many things. Your EGR valve being disconnected or inoperative will cause you to fail big time. Also an exhaust leak before the cat will do the same. High engine temps or a lean air/fuel mixture also contribute to high NOx. If your rig is running at a normal temp I wouldn't worry about running hot just yet. Excessive carbon build-up in the combustion chamber will cause high NOx. Just putting a new cat on will probably get you to pass, but I have no doubt you will need another cat in 2 years to pass again.

What to do first? Grab your smog check report and head over to this website: http://www.smogsite.com/calculators.html#lambda You might have to scroll down the page a bit to find the Lambda calculator. Start plugging in the info about your emission levels and percentages. Be sure to input them all exactly as shown on the smog check report. Click the calculate Lambda button and check the results by looking at the colored bar right below the calculate button. Now what this does is tell you if you vehicle is running correctly, not too rich or too lean. A lambda reading of 1.0 is considered perfect. As long as your reading is in the green section then you probably have a bad cat. If the reading is in any other color than green then you have to figure out why the engine is running rich or lean before doing any other repairs. This website is easy to use and will tell you pretty definitively what is going on in your engine. If the engine is running too rich or too lean, a cat isn't going to fix your problem. You may still need a cat, but at least you won't kill your cat and have to replace it again to pass smog next year. Oh, that's the other fun thing about being a gross polluter, you have to get your rig smogged every year for the next 3 or 4 years.

Start there, and please report back what the calculator said. If you want to post up your numbers and I can run them to see what I think.

Its an '89, straight 6.
 
dude just sell it to me, i will take it off your hands for $500. just get a new one its no good haha!!
 
Talk about the 'ol shotgun diagnosis. Everyone always says to put a cat and an o2 on it. Well....maybe. The big thing is why did the cat fail? What year is your rig? You said it has EGR so that is a Renix era rig.

High NOx can be cause by many things. Your EGR valve being disconnected or inoperative will cause you to fail big time. Also an exhaust leak before the cat will do the same. High engine temps or a lean air/fuel mixture also contribute to high NOx. If your rig is running at a normal temp I wouldn't worry about running hot just yet. Excessive carbon build-up in the combustion chamber will cause high NOx. Just putting a new cat on will probably get you to pass, but I have no doubt you will need another cat in 2 years to pass again.

What to do first? Grab your smog check report and head over to this website: http://www.smogsite.com/calculators.html#lambda You might have to scroll down the page a bit to find the Lambda calculator. Start plugging in the info about your emission levels and percentages. Be sure to input them all exactly as shown on the smog check report. Click the calculate Lambda button and check the results by looking at the colored bar right below the calculate button. Now what this does is tell you if you vehicle is running correctly, not too rich or too lean. A lambda reading of 1.0 is considered perfect. As long as your reading is in the green section then you probably have a bad cat. If the reading is in any other color than green then you have to figure out why the engine is running rich or lean before doing any other repairs. This website is easy to use and will tell you pretty definitively what is going on in your engine. If the engine is running too rich or too lean, a cat isn't going to fix your problem. You may still need a cat, but at least you won't kill your cat and have to replace it again to pass smog next year. Oh, that's the other fun thing about being a gross polluter, you have to get your rig smogged every year for the next 3 or 4 years.

Start there, and please report back what the calculator said. If you want to post up your numbers and I can run them to see what I think.


Here are the numbers and what i got.

% of O2 / 2.7
% of CO2 / 12.9
% of CO / .02

PPM of HC 79
PPM of NOX *3179*

Lambda came out to 1.144 / Air Fuel Ratio 16.82 Says I am running to lean. Any help?
 
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