Power FC Tuning/Smog help.

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06-11-10, 06:33 PM

Mobius0

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Tuning/Smog help.

I have a power FC with Datalogit, that was tuned, but won't pass smog. It's testing in the 200's for HC, which is way too high for here in CA. I talked to the person who tuned it (sadly he moved), and he said I should just lean it out just for the test.

I don't know of anyone around here who would be able to tune it, so I figure I might as well learn how to do it myself. I don't care about learning to tune it for better performance (I'll learn that later :P). I simply want to get it to pass smog, and then set it back to the current maps.

My first question, is what exactly do I need to get? Currently, aside from the Power FC and 3" exhaust, the car is all stock, except for a boost gauge I hooked up.

I assume I will need a wideband o2 sensor? And if so, do I just replace my narrowband with it, and hook it into the datalogit? Will I need an AFR sensor module and gauge?

Lastly, does anyone have any advice on how to tune it?

I've thought about just dumping alcohol in it, but I'm reluctant to do it that way, assuming it even works. Plus if I tune it to pass, I can use it again next time.

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06-11-10, 11:14 PM

arghx

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Exactly what do you have for exhaust? List all the mods.

And can you post the full smog test results?

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06-13-10, 01:27 PM

Mobius0

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It has full 3" exhaust with a Bonez highflow cat, and a 3" downpipe with no pre-cat.

The test results were:
<html>
<table style="text-align: left; width: 800px;" border="1" cellpadding="2" cellspacing="2">
<tbody>
<tr>
<td style="vertical-align: top; text-align: center;"> 
</td>
<td style="vertical-align: top; text-align: center;"> 
</td>
<td style="vertical-align: top; text-align: center;">% CO2 
</td>
<td style="vertical-align: top; text-align: center;">% O2 
</td>
<td colspan="3" rowspan="1" style="vertical-align: top; text-align: center;">HC (PPM) 
</td>
<td colspan="3" rowspan="1" style="vertical-align: top; text-align: center;">CO (%) 
</td>
<td colspan="3" rowspan="1" style="vertical-align: top; text-align: center;">NO (PPM) 
</td>
<td style="vertical-align: top; text-align: center;"> 
</td>
</tr>
<tr>
<td style="vertical-align: top; font-weight: bold; text-align: center;">Test 
</td>
<td style="vertical-align: top; font-weight: bold; text-align: center;">RPM 
</td>
<td style="vertical-align: top; font-weight: bold; text-align: center;">MEAS 
</td>
<td style="vertical-align: top; font-weight: bold; text-align: center;">MEAS 
</td>
<td style="vertical-align: top; font-weight: bold; text-align: center;">MAX 
</td>
<td style="vertical-align: top; font-weight: bold; text-align: center;">GP 
</td>
<td style="vertical-align: top; font-weight: bold; text-align: center;">MEAS 
</td>
<td style="vertical-align: top; font-weight: bold; text-align: center;">MAX 
</td>
<td style="vertical-align: top; font-weight: bold; text-align: center;">GP 
</td>
<td style="vertical-align: top; font-weight: bold; text-align: center;">MEAS 
</td>
<td style="vertical-align: top; font-weight: bold; text-align: center;">MAX 
</td>
<td style="vertical-align: top; font-weight: bold; text-align: center;">GP 
</td>
<td style="vertical-align: top; font-weight: bold; text-align: center;">MEAS 
</td>
<td style="vertical-align: top; text-align: center;">Results 
</td>
</tr>
<tr>
<td style="vertical-align: top; text-align: center;">15 mph 
</td>
<td style="vertical-align: top; text-align: center;">1708 
</td>
<td style="vertical-align: top; text-align: center;">13.44 
</td>
<td style="vertical-align: top; text-align: center;">0.96 
</td>
<td style="vertical-align: top; text-align: center;">89 
</td>
<td style="vertical-align: top; text-align: center;">277 
</td>
<td style="vertical-align: top; text-align: center;">287 
</td>
<td style="vertical-align: top; text-align: center;">0.53 
</td>
<td style="vertical-align: top; text-align: center;">2.03 
</td>
<td style="vertical-align: top; text-align: center;">0.79 
</td>
<td style="vertical-align: top; text-align: center;">708 
</td>
<td style="vertical-align: top; text-align: center;">1944 
</td>
<td style="vertical-align: top; text-align: center;">0151 
</td>
<td style="vertical-align: top; text-align: center;">FAIL 
</td>
</tr>
<tr>
<td style="vertical-align: top; text-align: center;">25 mph 
</td>
<td style="vertical-align: top; text-align: center;">1882 
</td>
<td style="vertical-align: top; text-align: center;">12.97 
</td>
<td style="vertical-align: top; text-align: center;">2.26 
</td>
<td style="vertical-align: top; text-align: center;">54 
</td>
<td style="vertical-align: top; text-align: center;">227 
</td>
<td style="vertical-align: top; text-align: center;">246 
</td>
<td style="vertical-align: top; text-align: center;">0.51 
</td>
<td style="vertical-align: top; text-align: center;">2.01 
</td>
<td style="vertical-align: top; text-align: center;">0.09 
</td>
<td style="vertical-align: top; text-align: center;">746 
</td>
<td style="vertical-align: top; text-align: center;">1744 
</td>
<td style="vertical-align: top; text-align: center;">0262 
</td>
<td style="vertical-align: top; text-align: center;">FAIL 
</td>
</tr>
</tbody>
</table>
 </html>

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06-13-10, 07:08 PM

arghx

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It will be a lot easier to see what's going on if you have a wideband. Now aftermarket cats are harder to pass than OEM ones, and having no precat makes the main converter temperature very important. Did you heat the cat up by boosting the engine before the test? Are you sure the air pump is working properly? In most types of driving there should be air flowing directly to the exhaust ports before the cat. Sometimes the air control valve will direct the secondary air directly into the cat through the split air pipe.

Buy you shouldn't necessarily need to lean the car out with the PFC. The airpump should be diluting the mixture at idle and then on these dyno tests the O2 feedback should be keeping the mixture lean.

is O2 feedback on? go look at etc. --> function select on your commander to check. it may have been turned off.

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06-13-10, 08:11 PM

Mobius0

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Quote:

Originally Posted by arghx

is O2 feedback on? go look at etc. --> function select on your commander to check. it may have been turned off.

O2 feedback is off.

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06-14-10, 12:39 AM

arghx

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Well that's a problem when you are trying to pass emissions.

If the car is as stock as you say, your best bet is to put the stock ECU back in. Drive it on the highway for a few minutes to heat up the cat, then take it in for inspection. Stay out of boost as best you can, but it's not a huge deal if it sees a couple psi at part throttle.

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06-14-10, 12:56 AM

cewrx7r1

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If you log the smog test with a DATALOGIT, you would know which area to lean out.
The same could be learned by viewing COMMANDER Monitor Map Trace.

Almost anyone can learn to tune idle and low load just by learning what the COMMANDER can do.

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06-14-10, 05:17 AM

Mobius0

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Quote:

Originally Posted by arghx

The car failed with a stock ECU already, and I always drive it for 20-30 minutes on the highway before taking it in. I think the highflow cat just isn't good enough.

Quote:

Well, I only have Datalogit, with no commander. But can I log the smog test without being in the car when they test it? What if I just logged it while driving under the same conditions as the test?

Also, back to my original question: Do I need to get a wideband O2 sensor to tune for it?

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06-15-10, 03:20 PM

arghx

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If it won't pass with the stock ECU then you've got something else going on. I think you're trying to tune around a problem. The stock ECU runs plenty lean when a lean mixture is necessary. It uses the O2 sensor feedback and the air pump to achieve the proper AFR. You can't "out emissions" the stock computer with tuning on a Power FC, not in your situation where all you have is exhaust on an otherwise stock car. I just don't see the point. You could lean it out too far and fail NOx tests. You could fiddle with it all day but still have a problem with your airpump, ACV, or something else.

It may be as simple as replacing the stock 1 wire O2 sensor, putting the stock ECU in, and making sure the cat is hot before you take it to get tested. Have you replaced the factory o2 sensor? You can get a Bosch universal 1 wire sensor at Autozone for cheap.

Quote:

I think the highflow cat just isn't good enough.

Yes, aftermarket cats are not as good for passing emissions. Why do you think they flow more and/or cost less than stock? They have less precious metals inside for catalyzing and they're not engineered for emissions like factory cats.

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06-15-10, 05:21 PM

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Mobius0

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Quote:

Originally Posted by arghx

I replaced the O2 sensor with a brand new one. I've also replaced my ACV, and all my vacuum hoses with silicone ones, and tested all the solenoids. Honestly, I've put so much effort into the ACV, that at this point, I don't even care anymore, if it's my problem.

I know the engine runs perfectly, since I just rebuilt it.

I do think that the engine in it is a 96+ JDM, because it has the Japanese Y-pipe, and had the simplified ACV (which I replaced with a US one.), so perhaps that also is contributing to my smog issues (and maybe even the stock ECU, if it is JDM?).

But I'm just simply running out of time to get this thing smogged, and whatever the problem is, I'm pretty certain it could be tuned to pass, at least for now. But I know very little about tuning and the Datalogit.

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