Thread: failed smog. help please?

Just went to get my 94 B13 smogged and it failed.



The only mods that were on it at the time included a flywheel, UR plulleys, and a magnaflow muffler. All smog equipment is still attached. I did remove my cai and header 2 days ago. I think the timing is off as the result of when I replaced my cap and rotor. So I'm going to perform the following:
-clean PCV valve
-clean AAC valve
-clean AIC vave
-clean EGR and carbon canister
-check timing

Is there anything you guys suggest on what to do or fix/replace in order to pass?

Here is more info on my car.
http://www.sr20forum.com/general-sr20/215397-dynoed-my-car-first-time-today.html

one thing i know is most of the time a car will fail because of a bad o2 sensor. in three occasions, my b13 and two friend's honda's, failed smog due to a faulty o2 sensor. we each replaced it, and it passed. well for my case, it was "one" of the reasons why it passed. second, i'd say if your catalytic converter is the original one, might want to think about borrowing one from a friend or getting a new one.

I agree that you should also check the O2 sensor. A bad O2 sensor will affect HC readings. There is a way to check whether it is cycling at the proper frequency by putting the ECU in test mode (if you can't find the procedure let me know and I will provide it).


If you retard your timing it should reduce NOX. I would set it at 13* BTDC for testing purposes and see if this helps.

But NOX is mostly affected by a properly functioning EGR system. Make sure that your EGR valve is opening when you rev the engine from idle (hold you finger on the bottom of the diaphram and rev the engine -- the diaphram should move up). If this does not happen, check your vacuum hoses and make sure that the BPT pipe is clear at the EGR tube that runs up from the header. If the BPT pipe is clogged, then you have to clean out the plug to get the EGR working.

Finally, a fresh change of oil helps with HC levels.

And, make sure the cat is plenty hot by driving the car hard on the way to the testing facility.

It also helps to cross your fingers while the testing is being done. Let us know how it goes -- there are other things that can be done.

Bill

I have a better O2 sensor, so I will install that.

I'll clean the EGR system

Timing is my biggest issue and it started ever since I replaced my cap/rotor. I tried timing it but the pointer mark above the pulley is missing. So I'm having it timed by bringing it to TDC and going from there.

My mom went with me to get it smogged and she hates driving fast (35mph) which kept me from getting the cat good and hot. I think I'll have my dad go this time.

^^^^ you could just rev the engine a lot to get it nice and hot if u dont wanna drive fast(and i would say 35 mph is not that fast, i hope u were on the freeway at those speeds. reminds me of the movie Revenge of the Nerd when they were driving to college. "tell you what son, kick it up to 37, lets look dangerous")

I'm pretty sure that the timing adjust pointer is just pressed into the engine cover. If you pull the front wheel and remove the splash shield in the wheel well, you might be able to see the hole or the stub. Perhaps you can clean the hole out and jury-rig something that will allow you to set the timing -- maybe select a drill bit of the correct size and tap it into the hole.

Failing that, when the distributor is positioned in the center of the mounting bracket (that is with the same amount of crescent-spaced space showing in the slot on both the firewall and the radiator side of the mounting bracket) the timing is pretty close to 15* BTDC. If you then pull the distributor toward the radiator (after loosening both bolts), you will be retarding the timing. Pull it all the way and you are somewhere around 8-10* BTDC and about half of that (that is half way between straight up and full forward to the radiator) will be around 13* -- the limit of factory specs.

This will reduce your base idle speed, so be prepared to put the engine in base idle adjust mode and increase your idle speed to about 750 RPM, or whatever the spec is.