Question about Dodge Dakota

1 Answer

99 dakota 5.2L, high nox, whats the most common cause of this?

Posted by on


1 Answer

  • Level 3:

    An expert who has achieved level 3 by getting 1000 points

    Top Expert:

    An expert who has finished #1 on the weekly Top 10 Fixya Experts Leaderboard.


    An expert that got 20 achievements.


    An expert that got 10 achievements.

  • Dodge Master
  • 76,673 Answers

Defective catalytic converters

Posted on Nov 12, 2009

Testimonial: "AAA+++"


1 Suggested Answer

  • 2 Answers

SOURCE: I have freestanding Series 8 dishwasher. Lately during the filling cycle water hammer is occurring. How can this be resolved

a 6ya expert can help you resolve that issue over the phone in a minute or two.
Best thing about this new service is that you are never placed on hold and get to talk to real repairmen in the US.
the service is completely free and covers almost anything you can think of.(from cars to computers, handyman, and even drones)
click here to download the app (for users in the US for now) and get all the help you need.

Posted on Jan 02, 2017


Add Your Answer

Uploading: 0%


Complete. Click "Add" to insert your video. Add



Related Questions:

1 Answer

NO ppm CA. smog at 15mph too high

NOX is high coolant or engine temps
& egr issues

Lots on the internet to study on exhaust gases
& the reason they fail inspection or are too hi

Mar 26, 2014 | 1995 Dodge Dakota

1 Answer

1996 dakota 4 cyl. won't pass smog test nox is 225 over limits. Asked smog tech it has no egr. I replaced 02 senser ,flushed cooling system, used seafoam as directed on bottle. All those steps dropped nox...

any leak above the o2sensor can throw everything off down the line.
be it a intake or exhaust, sounds to me like you found your problem allready,Gary

Oct 24, 2013 | 1998 Dodge Dakota

1 Answer

I have a 95 grand jeep cherokee and i have failed 2 emission they say it is a the NOx is to high what would cause that?

What causes High NOX Emissions

Thousands of technicians have faced the challenge of bringing a particularly stubborn application into compliance for NOx emissions. High NOx readings are a clear sign of performance issues somewhere in the system. The question is, where?
Among 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
Failed or malfunctioning catalytic converter
Corroded or damaged engine sensor electrical connections

Please note that while a failed catalytic converter will contribute to high NOx readings, the failure in itself may have been caused by some other upstream performance problem. In all cases, it is crucial to identify the root cause of the problem before blaming the converter.

Case Study

Oct 09, 2012 | Jeep Cars & Trucks

2 Answers

What is the egr system

EGR stands for Exhaust gas recirculating system

Apr 07, 2012 | Cars & Trucks

1 Answer

What are the causes for NXo reading

A high NOx reading can be caused by any conditions that make the engine run lean. Vacuum leaks will dilute the fuel/air mixture with excess air leading to lean running. Lean mixtures lead to high combustion temperatures which produce NOx.

A malfunctioning EGR valve will not recirculate enough exhaust gas to keep combustion temperatures in check. The primary purpose of this valve is to lower NOx emissions are high RPM. It does this by delivering some low oxygen content gas back into the intake stream to dilute the incoming mixture. By decreasing the oxygen, combustion temps are lowered.

By the same logic, a misfire can cause high NOx. If the fuel/air mixture is not burned, excess oxygen in the exhaust (catalytic feed gas) will cause a dramatic decrease in catalytic converter efficiency in reducing NOx

Jan 24, 2011 | 1988 Toyota MR2

1 Answer

High nox fail smog test any remedies? 99

NOX is created when the internal combustion temperature gets to high.The egr system uses burnt exhaust gases to line to cylinder walls.The purpose of this is decrease internal combustion temperature therefore reducing the amount of NOX created.Would look to a possible egr malfunction usually they will trigger the check engine light but not always.The 4.3L has been known to have issues with carbon buil up in the egr and the egr pintle not open and closing properly.

Jun 07, 2010 | 1999 Chevrolet Astro

1 Answer

1990 Dodge Dakota Smog Issue


PPM of Nox or Co or HC?????

The base of the EGR and the EGR air passage tube will collect carbon over the years.

Most car over 65,000 will fail Nox and has high CO because of the partly block passage.

The only way to clean to the air passage tube is with a lot of WD-40 or similar cleaner.

The EGR valve can be clean or replace under $68 ////gasket for around $3.

Make sure there is NO LEAK when you put the EGR valve back in place.

Please post what PPM is failing on reply.

Jul 06, 2009 | 1996 Dodge Caravan

1 Answer

My 1991 Saab 900 needs an ERG system is this hard to do my self ?

post the readings. does the car overheat?
NOX is caused by combustion temerature being too high. many possible causes. common ones are EGR system, running lean, deffective catylitic.

Jun 25, 2009 | 1991 Saab 900

1 Answer


nox is from running lean..... its realy high temps that cause this.......... replace the o2 sensors this should cure that any more help let me know

Oct 24, 2008 | 1993 Chevrolet Suburban

Not finding what you are looking for?
Cars & Trucks Logo

Related Topics:

247 people viewed this question

Ask a Question

Usually answered in minutes!

Top Dodge Experts


Level 3 Expert

76673 Answers

Colin Stickland
Colin Stickland

Level 3 Expert

22219 Answers

Jeff Turcotte
Jeff Turcotte

Level 3 Expert

8531 Answers

Are you a Dodge Expert? Answer questions, earn points and help others

Answer questions

Manuals & User Guides