hi everyone, i just took my car to get smog but it failed and need your help to figure out what i should do to pass it.
the car is a 1993 honda civic lx with a d15b7. the car is all stock and there is no cel.

the is the test result

 

Well by looking at the report your Nox is up for both 15 and 25mph.

So we need to look at what reduces Nox.

Your car has an EGR valve and I think that is your problem.

There are three things to check so here they are.

1. Pull EGR valve and check ports. They usually get plugged up with carbon and that defeats the EGR.
2. Check EGR valve for movement of the plunger. You might be able to see this when revving the motor with a flashlight thru a hole in the EGR valves case.
3. vacuum to the EGR valve. You should get 7 in.hg. from the vacuum line that is connected to it at 2200rpm.

However you might be able to get it by with a small retard of the timing.Small one I say because you only have a couple of degrees to play with. If Spec for timing is 16btdc. Set the timing to 14btdc. this might lower it just enough.

And if these don't do it you might have carbon build-up on the valves and pistons so you might want to seafoam the motor thru the intake manifold only.

 

ok so i just got to check the car and the car is not equipped with an egr system. so is running seafoam my best bet now, or are there other things i could check? thanks