Here are my smog results from today.


The engine is a 1999 USDM B16A2.
Short ram intake and 4-1 header.
Stock cat and exhaust.
Timing was at 16 BTDC.
Spark plug gap was within factory specs.
The car wasn't driven for about 2 weeks. When I did warm up and drive the car, I didn't go past 3K rpm in any gear.

The only area I failed was HC (PPM) at 15 mph. I almost failed HC (PPM) at 25 mph. Also almost failed NO (PPM) at 15mph.

Just wondering what I should do to pass smog when I retest? So far, from searching around, I've come up with:
Retard the timing
Increase the idle
Change the primary O2 sensor

Any help would be appreciated!

 

How old are the plugs, wires, cap, and rotor?

Any CEL codes?

Is the engine running cold (taking a long time to warm up)?

 

The plugs, wires, cap, and rotor are about 1.5 months old.

Only cel is code 91 for FTP.

It does seem to take a long time to warm up. My other car gets to operating temps a lot faster.

 

Your thermostat may be stuck open. If the engine cannot reach operating temp, then the ECU uses a rich preprogramed air-fuel ratio (open loop). Consider replacing the thermostat with an OEM one.

 

What I see sticking out is the amount of 02 in the exhaust. Check for exhaust leaks before the cat. If you have any exhaust leaks before the cat it will mess up your air/fuel ratio (if it is before the first 02 sensor) and the cat (Cat will not get hot enough to do it's reduction) So check this first!! then we will go from there.

Your normal 02 reading should be 0.4% or lower at the 15mph and 0.2% or lower for the 25mph.

 

That's where the temp needle is at after warming up. Is that the appropriate range?

Oh, forgot to mention, I do have a 4-1 header and it DOES whistle a bit when under load. The header is actually dented near the oil pan. What's the best way to determine where the leak is at?

 

The temp gauge reading looks fine. If it takes quite a bit of time to reach that reading, then replacing the thermostat may be worthwhile.

As mentioned above, an exhaust leak upstream or near the primary O2 sensor would also cause the engine to run rich.

 

Alright, will look for leaks tomorrow.

I probably should have mentioned this earlier, but I have a short ram intake as well.
If there is a leak in the intake piping, would that also cause me to run rich?

 

No

Is the IAT sensor properly installed?

 

put back your stock header and since its HC that fail'd its an egr. replace that egr or clean it good.

 

The B16a2 does not have an EGR system.

 

I don't have the stock header, bought the car with the existing swap.

I will work on looking for leaks tomorrow.

Quick question though. Theoretically speaking, if the front tires were a bit low on air, would that affect the smog test results?

 

No

 

This honestly helped me pass smog. its only like 10 bucks.

 

The short ram intake seems to be out of some other car? There are two IAT sensors on the SRI. One is in the middle of the piping and the other is near the intake manifold. From what I see, the IAT is installed correctly. The one near the intake manifold is the one that the male end is plugged into. The plastic bung that the IAT is plugged into is in good shape as well. The other one closer to the mid of the intake is sort of cracking.

I jacked up the car today and looked for leaks. Turned the car on and put a towel on the muffler and listened for any hissing. I didn't hear anything, so I used a soapy solution and sprayed the header. I didn't see any bubbles forming so it doesn't seem like the header is leaking.

I heard that stuff doesn't work and is a waste of money.

 

Anything else I should look for to diagnose the problem folks?

 

Would changing the PCV valve help?

 

Ok, so I passed the smog today and here are my new results.



Before the smog check I:

Changed the O2 sensor
Changed the oil
Changed the PCV valve
Drove the car hard

I still have a question about my high HC at 15mph though. I BARELY passed and was right at the limit.
Just wondering if you folks could help with any suggestions on lowering my HC.
Should I try running seafoam to clean out my injectors?

Any help is appreciated. Thanks.