Test Only Smog help?

[MJR]

Gotta disagree guys. The only failure is on NOx...A CAT is not the answer. And having it hot will only increase the NOx. Hot motor is to get rid of HC's which he is not high on.

Wrong!. Here's some reading material and a link. The following is from this site http://autorepair.about.com/cs/generalinfo/a/aa080401a.htm It is likely he got the wrong cat. NOX is created by high combustion chamber temps so a overheating engine or lean running can make the problem worse. So an O2 sensor could help along with regular service (tuneup/cap/rotor/wires and a combustion chamber decarb if needed) and a good cat conv.



"Catalytic converters can either be an oxidation or three-way type. Oxidation catalysts convert carbon monoxide (CO) and hydrocarbons (HC) to carbon dioxide (CO2) and water, but have little effect on nitrogen oxides (NOx) and particulate matter. Three-way catalysts operate in a closed-loop system together with a lambda, or oxygen, sensor to regulate the air/fuel ratio on gasoline engines. The catalyst can then at the same time oxidize CO and HC to CO2 and water while reducing NOx to nitrogen.

Most cars today are equipped with a three-way catalytic converter. The term Three-way refers to the three emissions it helps to reduce, carbon monoxide, hydrocarbons or volatile organic compounds (VOCs) and NOx molecules. The converter uses two different types of catalysts, a reduction catalyst and an oxidization catalyst. Both types consist of a base structure coated with a catalyst such as platinum, rhodium and/or palladium. The scheme is to create a structure that exposes the maximum surface area of the catalyst to the exhaust flow, while also minimizing the amount of catalyst required."

 

[cracker]

That is the PROBLEM.

Actually it was ridiculously hot! :flame: I ran it for 1/2 hour basically rev'd out full bore trying to get the thing hot and it was probably hotter than anytime I have ever used it before.

As far as the 'right or wrong' cat, it was the same cat that got Paul's '96 passed. Still does not answer whether it is the 'right or wrong' cat but it worked three weeks ago. Paul's problem, as I am sure you read, was HCs.

 

[JohnX]

Wrong!. Here's some reading material and a link. The following is from this site http://autorepair.about.com/cs/generalinfo/a/aa080401a.htm It is likely he got the wrong cat. NOX is created by high combustion chamber temps so a overheating engine or lean running can make the problem worse. So an O2 sensor could help along with regular service (tuneup/cap/rotor/wires and a combustion chamber decarb if needed) and a good cat conv.



"Catalytic converters can either be an oxidation or three-way type. Oxidation catalysts convert carbon monoxide (CO) and hydrocarbons (HC) to carbon dioxide (CO2) and water, but have little effect on nitrogen oxides (NOx) and particulate matter. Three-way catalysts operate in a closed-loop system together with a lambda, or oxygen, sensor to regulate the air/fuel ratio on gasoline engines. The catalyst can then at the same time oxidize CO and HC to CO2 and water while reducing NOx to nitrogen.

Most cars today are equipped with a three-way catalytic converter. The term Three-way refers to the three emissions it helps to reduce, carbon monoxide, hydrocarbons or volatile organic compounds (VOCs) and NOx molecules. The converter uses two different types of catalysts, a reduction catalyst and an oxidization catalyst. Both types consist of a base structure coated with a catalyst such as platinum, rhodium and/or palladium. The scheme is to create a structure that exposes the maximum surface area of the catalyst to the exhaust flow, while also minimizing the amount of catalyst required."

How can you say I am wrong with any authority? I did not say any of you were wrong, just that I disagree and I offered possible solutions to the problem. NOx is obviously caused by high combustion temps and can be helped by high humidity (or water injection ) and that was the basis for my answer. I don't KNOW if his Jeep has other problems, I was just suggesting a way to get it passed without having to spend big bucks "fixing" things.

 

[cal]

$20 says if he just changes the o2 sensor it passes.

 

[JohnX]

I got 20 that says all he has to do is spray some water in the intake while testing and it passes

 

[cal]

I'll confess I was only looking at realistic solutions..

 

[JohnX]

I'll confess I was only looking at realistic solutions..

It works if you know the smog tech.

 

[MJR]

Alright all I can do is bitch but what really pisses me off is half-assing something instead of fixing the damn problem right. Do what you will I don't really f*@%ing care. Of course how many parts do you want to shotgun to to find the problem and how much are you going to spend before you find the right one. Don't believe me, just ask Remi. Ok so I am a dealer tech (the ones everybody says are ripping you off, FU) and have been working around Jeeps since 87/88, but what do I know. That's all for now folks, have a nice day.

 

[MJR]

How can you say I am wrong with any authority?

The only failure is on NOx...A CAT is not the answer.

Three-way catalysts... The catalyst can then at the same time oxidize CO and HC to CO2 and water while reducing NOx to nitrogen.

Based on the quotes above you felt that a catalytic converter had no affect on NOX tailpipe emissions, correct?

 

[Bryan C.]

Alright all I can do is bitch but what really pisses me off is half-assing something instead of fixing the damn problem right. Do what you will I don't really f*@%ing care. Of course how many parts do you want to shotgun to to find the problem and how much are you going to spend before you find the right one. Don't believe me, just ask Remi. Ok so I am a dealer tech (the ones everybody says are ripping you off, FU) and have been working around Jeeps since 87/88, but what do I know. That's all for now folks, have a nice day.

Mike, I feel your pain. Just because you can fix cars in real life every single day doesn't mean that people are going to listen to you. This is exactly why I don't respond to these posts anymore. A well worded PM seems to be more effective and cause less turmoil for the guy asking for help.

 

[Gerr]

Alright all I can do is bitch but what really pisses me off is half-assing something instead of fixing the damn problem right. Do what you will I don't really f*@%ing care. Of course how many parts do you want to shotgun to to find the problem and how much are you going to spend before you find the right one. Don't believe me, just ask Remi. Ok so I am a dealer tech (the ones everybody says are ripping you off, FU) and have been working around Jeeps since 87/88, but what do I know. That's all for now folks, have a nice day.

Mike, We all know you are the jeep guru and I for one totally understand your frustration. Youve help me out by just asking questions on more than one ocasion and you have always been more than willing to try and help in any way you can. I salute you sir! :cheers: you are one of few people on here I wana learn from.

"Do what you will I don't really f*@%ing care" Umm Mike we all care cuz when some thing half assed breaks on the trail we all end up waiting or helping fix it again if nothing else in another half assed way to get them and everyone else off the trail. I for one enjoyed your knowledge on the trail and you helped get my heep off the trail and even helped clean up the mess my oil pan left.

 

[MJR]

I did not say any of you were wrong, just that I disagree and I offered possible solutions to the problem. NOx is obviously caused by high combustion temps and can be helped by high humidity (or water injection ) and that was the basis for my answer. I don't KNOW if his Jeep has other problems, I was just suggesting a way to get it passed without having to spend big bucks "fixing" things.

Yes an O2 sensor can cause it to run lean (high NOX or rich/high HC), yes NOX forms in very high combustion chamber temps and yes water injection can reduce NOX by cooling the combustion chamber temps.

There are other things that can cause it like, intake air leak (extra air getting in causing a lean condition), exhaust leak (extra air getting in affecting O2 sensor readings), bad catalytic converter (not reducing NOX to nitrogen), combustion chamber carbon buildup (changing compression ratio), etc...

 

[JohnX]

Mike...I'm not arguing with you. Everything you've said make sense, but sometimes you just want to pass smog. Like I said, I was making suggestions on how to get it passed, not on what the cause might be. I gave up internet diagnosis a long time ago. Avery simply wants it to pass, from what I gather...how it passes doesn't matter.

Peace man....I know you're good, you know you're good, so lets not get upset about this.

 

[MJR]

I not really upset, just joshin.

 

[JohnX]

I not really upset, just joshin.

Cool...Hard to tell in Black and White

 

[MJR]

Cool...Hard to tell in Black and White

Exactly that's why most misunderstand without seeing the persons expressions in real life.