Smog check fail

IVAN95

MEMBER
1998 DODGE MAGNUM
V6
177,945 MILES

Hello my name is Ivan, live in the Richmond CA.

If anything is close by I would really appreciate if you get in touch with me, I recently bought the vehicle listed above and took it for smog but it failed due to no (ppm) too high? I'm not a mechanic this is why i'm posting this message. I bought it so I can keep on working i'm a handyman, I was beating up my convertible Mustang so decided that I need yo buy a truck. So now that I got it before I ignore the problem I want to solve it and make it last enough to save up for a newer truck.
The truck runs no check engine light but some kind of smoke does come out the interior vents. So no wonder it's taped. Please anyone that can help me solve this I would appreciate it. Now I do not have a lot of money to afford a expert or to get it all fixed but if you work out with me I will really pay you. I'm 25 years old and have a beautiful 4 year old daughter depending on me. I do not have time to waist or lie so please if you can help and have time please contact me.

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1 Reply

KASEKENNY

MECHANIC
18,907 POSTS

You have two issues. The smoke coming out of the vents is a different issue and is most likely a heater core issue. So let's address the smog test and we can start a new post for that issue.

The failing of NOx is due to a couple possible issues. First and foremost is a lean misfire. Basically this is telling you that there is raw fuel going through the exhaust and the converter is not reducing the amount of NOx enough and it is emitting it to the atmosphere. So that means you are putting too much fuel through to the exhaust and it can't handle it due to a misfire. You said the vehicle is running properly so let's not go for this right now.

The next most likely cause is the exhaust catalytic converter has failed and it cannot reduce the NOx like it should. This is a harmful byproduct of fuel and needs to be reduced which is what the converter does. When it cannot do this, it just emits it to the atmosphere.

The last most common cause is a failed EGR system. However, you again have no running issues or check engine light so I doubt this is the issue.

Here is a guide that will help with this:

https://www.2carpros.com/articles/smog-test-inspection-information