hello well for some reason my car dumps out too much NOx emission. Does anyone know what causes this and how to fix it. I have a injen cai, stillen y-pipe, and a greddy exhaust does any of those affect it. Thanks in advance

 

One of the causes for high NOx emissions is by too lean of a mixture. Too lean of a mixture creates higher cylinder tempatures. Here is an article that can help you resolve your vehicles pollution problems.
http://www.car-forums.com/s9/t2590.html

I found some more information regarding high NOx readings. here is a good link to read up about emissions & cures. http://www.interro.com/techgas.html#anchoreleven

The info i posted below VVVVVVVVVV is taken from this article http://hostingprod.com/@aa1car.com/library/tr1196.htm

NOX failures are usually EGR-related, since the EGR system is primarily responsible for reducing oxides of nitrogen. But NOX emissions can also be caused by a bad three-way converter or a computer control system that remains in open loop.

PERFORMANCE CHECKS

There are four things you should always check on every vehicle that has a computerized engine control system:

1. Scan for fault codes. Any codes that are found need to be dealt with before anything else.

2. Make sure the system is going into closed loop. No change in loop status often indicates a coolant sensor problem.

3. Confirm that the system is alternating the fuel mixture between rich and lean. This is absolutely essential for the converter to function efficiently. You can do this by observing the O2 sensor’s output with a scan tool, or directly with a digital storage oscilloscope or voltmeter. If everything’s okay, the sensor should be producing an oscillating voltage that flip-flops from near minimum (0.1 to 0.2v) to near maximum (0.8 to 0.9v). O2 sensors in feedback carburetor applications have the slowest flip-flop rate (about once per second at 2500 rpm), those in throttle body injection systems are somewhat faster (2 to 3 times per second at 2500 rpm), while multiport injected applications are the fastest (5 to 7 times per second at 2500 rpm).

4. Confirm that the system responds normally to changes in the air/fuel mixture. To test the system’s response, pull off a vacuum hose to create an air leak (not too large or the engine will die). You should see an immediate voltage drop in the O2 sensor’s output, and a corresponding increase in injector dwell or mixture control dwell from the computer. Making the fuel mixture artificially rich by injecting some propane into the intake manifold should cause the O2 sensor output to rise and the computer to lean out the fuel mixture.

I hope that can help you out.

 

Thanks man im gonna check out those things today

 

Anytime!!!!!!!!