Post by
subtle_driver »
https://forums.nicoclub.com/subtle-driver-u44195.html
Fri Nov 14, 2008 9:41 pm
so you failed nox? you didn't fail hc? hmmm, i would suggest going through and testing the egr function, and all the vacuume lines and hoses that go with it. if you fail nox that basicly means your combustion temps are too high, i believe besides egr, it can also caused by lean mixture and engine temp too high. but EGR affects it the most.
first check to see if the egr valve is working. suck on the vacuume line going to it and see if it makes the engine stall or stumble (pass if it does, no cleaning needed. fail, if idle doesn't change much; clean it), then if it does, check to see if it holds vacuume(good if holds vacuume, if not, fail! get one that works). then check the transducer? does this have one? its too cold to go outside and check my car. many times the exaust backpressure rubber hose is broken and leaking. then check the functionality of the solenoid. there are three passages, i think.... you ad power to the unit, and it will *click* and one passage will close and open for the other side. basicly a valve that opens/switches electronicly when the ecu tells it to. you should also have a vaccume source that is not leaking or weak to the solenoid.
why did he tell you to clean the egr canister? what is that? there is a canister that is for fuel evap.
if you take your car to a 'Test only' station, don't take them too seriously. because they never fix cars to pass smog. it is illegal for them to do that. they lack experience. if your car is gross polluter, you can take it to Gold shield station. they fix your car for up to $500. or take it to a repair station. they know more and can diagnose it. if you want to do it yourself. make sure you have a vacuume gauge, and a troubleshooting guide. the vacuume gauge will tell you if your egr system is accuating or not. a good test after doing repairsl; install the gauge on the egr valve line and see if the tool shows vacuume when the egr is supposed to open, i think when you warm it up so the ecu is in closed loop, then rev the engine untill you see movement in the needle. or you can rig it to watch when you drive.