What are the NOx levels in my car?
I also installed a NOX-reducing cat. After these changes, it barely passed the 15-mph emissions test and still failed the 25-mph test for NOX. The exhaust readings at cruise are as follows: CO, .01%; HC, 12 ppm; CO2, 15.0%; NOX, 917 ppm.
Why was my NOx too high on the smog test?
The only emission that was above the limit during the smog test was NO, however both HC and CO measurements were about halfway between “average” and maximum. A 2nd website said, “High NOX emissions are almost always due to a defective EGR valve (or some component that controls the operation of the EGR valve).
What causes high NOx and high HC in an engine?
With excessive preignition, the early flame front comes in contact with the spark ignition flame front. This will result in high HC, low CO, high 02, low C02, and high NOx. The horsepower of the engine will suffer as well.
What causes a high NOx reading on a gas analyzer?
As a result of late intake valve opening, the vacuum will be low, causing the MAP sensor to see a load adding more fuel, causing high CO. The gas analyzer will read high HC, high CO, low O2, low CO2, and high NOx.
What to do if your car fails the NOx test?
If you own a non-EGR equipped vehicle, and have failed the emissions test for high NOx, pay close attention to the Catalytic Converter. Read about Catalytic Converter
The only emission that was above the limit during the smog test was NO, however both HC and CO measurements were about halfway between “average” and maximum. A 2nd website said, “High NOX emissions are almost always due to a defective EGR valve (or some component that controls the operation of the EGR valve).
Why does my car have a high NOx reading?
A 2nd website said, “High NOX emissions are almost always due to a defective EGR valve (or some component that controls the operation of the EGR valve). A related symptom that usually occurs when EGR is lost is spark knock (detonation) during acceleration.”
What causes high NOx in a fuel mixture?
1. Lean Fuel Mixture – Lean fuel mixtures cause high NOx. A lean fuel mixture exists when less fuel then required is delivered to the combustion chambers or when more air then necessary is added to the fuel. In either case the lack of gasoline needed to cool the combustion chambers down is not present.
What causes NOx to increase to an abnormal level?
Let’s consider the things that can cause NOX to increase to an abnormally high level. Oxides of nitrogen (NOX) are formed when the combustion chamber temperature exceeds 2500°F (the ignition point for compressed nitrogen). The engine must normally be under some kind of load before it develops such high combustion chamber temperatures.
Why does my Jeep have high NOx levels?
As you correctly surmised, combustion chamber deposits can artificially raise the compression ratio and encourage the formation of NOX. Overadvanced ignition timing can also cause NOX formation. Since the Jeep does not have an externally adjustable ignition system, we should be able to rule it out as a possible cause in this case.
Why is my NOx reading so high at idle?
Adding a load pushes the combustion chamber temperature to the point where NOX formation increases to an unhealthy level. The engine should be producing almost no NOX at idle. If the NOX reading is high at idle, run through the NOX-influencing factors I’ve listed until you find the cause.
What causes high No ( Nox ) in the air?
What Causes High NO (NOx)? Nitrogen Oxide or NO is created when an engine’s combustion chamber temperature reaches over 2500F. Vehicle manufacturers have designed several systems, which when working properly, lower nitric oxide emissions.
Why are NOx emissions bad for the environment?
NOx (or nitrogen oxide) is a chemical in automotive exhaust that gets created when the temperature inside a vehicle engine’s combustion chamber exceeds 2,500 degrees Fahrenheit. It is a pollutant that helps create smog, acid rain and particulate pollution. This can cause health problems for people exposed to it
When do you get high NOx in your car?
Remember high NOx nitric oxide is created when an engine’s combustion chamber temperatures reach over 2500F. You will want to make sure your vehicle’s cooling system is working properly, and your vehicle’s temperature gauge is always indicating normal.
When does the EGR system cause high NOx?
The EGR system’s job is to re-route a small amount of exhaust gas back into the intake manifold to help reduce combustion chamber temperatures. As mentioned above NOx is created when combustion chamber temperatures reach above 2500F.
I also installed a NOX-reducing cat. After these changes, it barely passed the 15-mph emissions test and still failed the 25-mph test for NOX. The exhaust readings at cruise are as follows: CO, .01%; HC, 12 ppm; CO2, 15.0%; NOX, 917 ppm.
Adding a load pushes the combustion chamber temperature to the point where NOX formation increases to an unhealthy level. The engine should be producing almost no NOX at idle. If the NOX reading is high at idle, run through the NOX-influencing factors I’ve listed until you find the cause.
As you correctly surmised, combustion chamber deposits can artificially raise the compression ratio and encourage the formation of NOX. Overadvanced ignition timing can also cause NOX formation. Since the Jeep does not have an externally adjustable ignition system, we should be able to rule it out as a possible cause in this case.