hello, im trying to smog my car to get it back on the road again..
the motor is h23 block with a 22 head
everything stock except for an AEM intake

havent changed the cat, or the o2 sensor...
everything else for the most part has been changed

on the way to the smog shop the car threw a random CEL.. i pulled over to check the code. i shut off the car to check the code and nothing popped up.. ghost code.. just my luck.. turned the car back on and the code was gone..

im so stumped as to how i can fail the 15mph tests but all of the 25mph passed.
any ideas? someone mentioned to me that maybe the timing is off...

 

anyone??

 

How old is the car and has the cat ever been replaced? If you got 200k miles on the car and the cats never been replaced that may be an issue.

 

i recently bought the car it has 190k on it.. and it looks pretty stock..

 

Well, lucky you, sounds like a bad cat. Not exactly the kinda part you just throw at a problem though, give the EGR system a thorough checking-out first, just to make sure it's doing its' job.

 

cali legal cats are hard to come by though.. im stumped

 

Your cat looks fine, since the O2 is below 1%. Seems like you might be running a little rich. Check out your EGR system for sure though. If you can, check to see what your fuel pressure is at with and without the vacuum source to the fuel pressure regulator. Also check to see that your fuel pressure does not drop after you turn the key off after priming the fuel system.

 

i ordered a new o2 sensor today and im gonna try to clean out the egr system tomorrow..

hopefully attempt to smog it again within the next couple days...

 

If your cat has not been replaced more than likely its time. Magnaflow sells CARB approved cats. Even if you pass the emissions portion you will still fail the visual which will result in a smog failure. might wanna get that fixed as well before you retest.

 

Question. Why would a cat work at one speed but not another. If the cat is bad, its bad, he wouldnt pass one part of the test and not another. He might have a slight misfire. There is deffinately something wrong with the EGR system since its main purpose is to lower NOx and its not doing that. Also check your PCV system

 

pcv valve? should i change it?

 

Go for it, they cost a dollar or two and take maybe 30 seconds to replace. No tools required.

However if you do want to check it, while the engine is running, pinch the pcv hose, then let go. If it clicks upon releasing it, then it's good. Or if you take it out and shake it, you should hear a rattle.

btw: your pcv valve lies ontop of your valve cover, its a small hard plastic piece with a 90 degree turn in it, kinda like a stunted "L."

 

good point. I didnt bother looking at his VIR. Didnt notice he passed on the second run.

 

so i cleaned out the egr valve yesterday.. and im waiting for an o2 sensor suppposed to be delivered today.. hopefully i can smog again tomorrow or saturday

 

changed the o2.. ran the car hard for 100 miles..

passed smog... real clean too.. thanks for all the help...

my car still throws the occasional ghost code though.. usually when im on the freeway it'll pop up.. but when you try to check the code nothing comes up... any ideas?

 

just smogged my 4th gen two weeks ago, i failed the 15 mph test but not the 25. My car was throwing high NOx levels, Bought a cat and fixed the problem, it passed with flying colors. Its the CAT! lol

 

NOx is not only determined by the cat. Just because it worked for you doesnt mean its the same problem for another person.

 

yeah i failed all of 15mph, i didnt change my cat.. it was good... o2 was probably the culprit

 

Mine failed when I was putting it on the road my test was almost the same as yours and i didn't spend a dime. All i did was pull the EGR and cleaned it out with carb cleaner and a plastic brush, and it passed with flying colours. But I also took the car for a 45 minute rip so the cat was hot, cleaned my K&N air filter and pulled the spark plugs and brushed them of. Iv'e got 235000 on my 95 srv so should be no problem for you.

Cheers