Dec 11, 2007 · There are two primary ways a car controls NOx. controlling the cylinder temps with the EGR system, which basically displaces a wee bit of incoming air (and its constituant oxygen) with inert exhaust gas. It’s exectly the same effect as closing the air supply a bit in a woodstive, it lowers the temp. Oxygen is a major requirement for combustion.

Mar 25, 2014 · By all means check the EGR system out. That allows a wee bit of inert exhaust to be drawn into the intake under load, thus keeping the cylinder temps from becoming hot enough to ramp up production of the NOx in the first place. If cylinder temps spike, NOx production increases. But also start saving for a new cat converter next year.

Jul 6, 2011 · Excessive NOx is formed by high coombustion temps, and the two primary methods used to control it are the Exhaust Gas Recirculation (EGR) system, which displaces a bit of incoming oxygen with inret exhaust gases when the engine is under load to keep temps down, and the catalytic converter, which contains a catalyst that when heated seperates ...

Jul 31, 2011 · My 1992 Honda Accord failed the emission test today for a too high NOX reading. The applicable standard is 2.50 and my car’s reading was 2.61. I’ve read that high NOX has something to do with a malfunctioning EGR valve. Will replacing the EGR valve guarantee that I pass the emissions test? I don’t want to start throwing money at all kinds of parts. Should I buy genuine Honda brand parts ...

Oct 1, 2010 · Having a new one (code detected) put in now and the price was no fun. So after a NOX sensor senses NOX, what does it do about it. I have no emissions test requirement. So could this have been a ‘Who Cares’ moment and money saved, or does the vehicle need a correct readout to run right? 2000 Subaru Legacy with 87K. Thank you.

Jun 22, 2009 · I’ve got an '87 Jeep Wrangler with a 4.2l straight six that just failed it’s emissions test here in CA and I was hoping somebody might be able to point me to the problem. The engine has 250k miles on it - I rebuilt it a couple of summers ago when it had about 225k so it’s got about 25,000 on it. The motor is tight, and runs well - standard mileage etc. The problme is the that NO ...

Oct 22, 2007 · I have a 1992 Nissan Maxima GXE, the car failed NOX emissions with a 6.25 (allowable is 3.25). EGR functions, Replaced O2 sensor (still didn’t pass lowered to 5.25). I am looking for another direction to go in. Any ideas would be great.

Jun 26, 2017 · The EGR was introduced purely as an emissions device (to dilute the incoming charge with pre-burned gasses which leads to lower combustion temperatures so NOx would not form). Years ago it was standard practice with a number of us mechanics at the dealer I worked at to disconnect them during new car prep.

Sep 30, 2018 · I really need some advice. I have a 2005 chevy tracker. It came from the factory with a 2.0 suzuki engine. It has failed emission 3 times for NOx. 6 months ago, had the top of motor rebuilt. Coolant is good, fan is running, car does not over heat. 1 time fail, changed the Cat Converter. I don’t remember the data for NOx 2 time fail, changed the EGR Valve. NOx 1000+ (when I picked the car up ...

May 4, 2009 · Only the emissions test can label a car a Gross Polluter. Emissions measured include Carbon Monoxide (CO), Carbon Dioxide (CO2), Hydrocarbons (HC) and Oxygen (O2). In California’s most polluted urban areas (Enhanced Areas), the emissions test also measures levels of oxides of nitrogen (NOx).” Note: I don’t live in one of the polluted areas.