y the couple gallons of high octane race fuel? doesnt it make it rich? im not sure about what high octance really does?

 

How new is your oxygen sensor?

 

Did you increase the idle speed as I suggested? If not, why not?

 

race fuel so it will burn hotter... less HCs

 

o2 censor and idle are fine

 

How did you test the o2 sensor? What do you mean by a 'fine' idle? Have you set it to the maximum allowable under the test?

 

Should it be set to 950? It's higher than that right now

 

idle is set at 1400

 

Unless it has changed, California law requires idle to be under 1000 rpm. If idle is not passing emissions at 1400 rpm, then idle is not the issue.

 

I think it's either the pulley or computer.
Could the M2 ECU be affecting idle?

If not, then it's on to testing the o2 sensor.

 

You are right, it's 1000.

 

OK, let's go at this a different way. Replace the ECU with an Apexi PFC, then you can tune your fuel at idle to lean it out enough to pass the smog test and your left with a much better ecu to boot! Plus you avoid the cost and labor of all the other stuff you mention. . .(no guarantee, but seems like your car is close to passing, just too rich at idle!)
--Jeff

 

This would cost more than what I had in mind

 

are you running the car hard before you smog. i usually drive the car around for at least 15 min to heat everything up and then idle it while i wait for the tech to be ready. fd always passed this way. same thing worked on a old volvo i smogged, it failed BAD then i ran it hard took it back next week and it passed w/o a problem.

 

The M2 ECU is essentially equivalent to the stock ECU at idle AFIK and there is absolutely no reason that a properly running FD with a stock cat should fail at idle (assuming new plugs (stock 7s and 9s), wires, oil and filter change). I'm still betting on a faulty O2 sensor; failing that, leaky injectors or a bad cat.

 

You don't think the pulley could be causing this?

 

These are realistic proven choices:

* OEM cat used for testing (buy or borrow new is $1k).
* retard timing to legal limit (works every time on my old CRX)
* Denatured alcohol lowers HC but raises NOx (you have to figure out the ratio - last resort).
* Sea Foam (deep creep) in the intake via vacuum. this is your best and cheapest solution. The only problem is it will smoke so bad the neighbors will call the fire dept, so do when no one is home or find an empty parking lot somewhere.

 

.

 

I don't think it's the o2 sensor because it's passing great at 2500. I did a computer diagnostic check and the computer output codes for the knock sensor and the egr switch. Any input?

 

The O2 sensor signal is only used at idle or during light throttle/cruise.

 

Turns out the pulley fixed it. With the Pettit pulley I was getting over 250 HCs at idle, I switched it out with the stock pulley and set the idle to 1000 and the HCs are nearly zero now. Thanks everyone

 

Afik?????