- If you need clarification, ask it in the comment box above.
- Better answers use proper spelling and grammar.
- Provide details, support with references or personal experience.
Tell us some more! Your answer needs to include more details to help people.You can't post answers that contain an email address.Please enter a valid email address.The email address entered is already associated to an account.Login to postPlease use English characters only.
Tip: The max point reward for answering a question is 15.
Check the ports if there is any carbon,I doubt it,
but you got to look
I would make sure you don't have overheating issues
That is the cause of NOX (High Combustion Temp)
Check fuel pressure
Use synthetic oil in engine
Check PCV Hoses etc
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.
NOX is produced when cylinder temperatures exceed 2500 f.
Your vehicle has 2 ways to directly reduce NOX, EGR system, and catalytic converter, and also the cooling system indirectly.
Take a look at the EGR system, vacuum lines, pipes, and make sure the diaphragm moves. Disconnect the vacuum line, then push on the diaphragm and plug the hole (from vacuum line) when you release the diaphragm there should be vacuum. Also you may want to take it out and give the EGR passages and EGR valve a good cleaning, with some type of carbon cleaner like carb cleaner.
We had to have the calatic converter replaced. We did this after doing an oil change, air filter change, and new spark plugs and still hadn't passed smog. After changing the calatic converter it passed smog with scores of 25.
CA you can take the car to a referree and get a one time waiver if you have spent a minimum of $450 on repairs not including smog fees. Gives you two years to get it fixed.
Smog Referee Call Center Toll Free: 1.800.622.7733
You can also sell the car to the state for "up to" $1,000