Failed State Emissions Inspection !!! Doh!!!

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Mar 3, 2003 | 07:20 AM

seebeew

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From: Long Island, New York

Failed State Emissions Inspection !!! Doh!!!

I was told that my O2 sensor was rotted away and that I had an exhaust leak (where the sensor is). I knew of the exhaust leak but figured it was at the manifold.??? The truck passed emissions the last three years with that same exhaust leak. Would a bad O2 sensor be the culprit of my failing? I did a tunup about 12k miles ago and it runs good. Any input??? Thanks

Mar 3, 2003 | 07:41 AM

whittey

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Failed State Emissions Inspection !!! Doh!!!

What part of the test did you fail? A bad O2 should give you lots and lots of HC. When the O2 goes bad (and if the ECU knows its bad), the ECU will pump tons of excess fuel in there to make sure you don't lean it out and blow up. This also absolutely kills your HC's and should drop your mileage.

-=Whittey=-

Mar 3, 2003 | 11:45 AM

seebeew

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Failed State Emissions Inspection !!! Doh!!!

I failed the Hc and Co I believe.

Mar 3, 2003 | 02:44 PM

Ford_Six

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From: The Big, Oregon

Failed State Emissions Inspection !!! Doh!!!

HC and CO are very closely linked. High Co readings are caused by incomplete combustion, like running too rich. Likewise, high HC is caused by rich mixtures, but can also be caused by an overly lean mix that causes a lean misfire. In that case, the high CO is actually produced in the cat and exhaust sytem. From what you have said, though, it seems like a rich mix is the problem. But don't take the inspectors advice. Have a shop check it out. Sometimes it is better to pay the $65 for a diagnostic, rather than chase ghosts. And yes, a bad O2s can cause this.

Mar 3, 2003 | 10:31 PM

steve83

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From: Memphis, TN

Failed State Emissions Inspection !!! Doh!!!

It's also very important to keep the engine running and hot while you're waiting in line at the test facility. I recently breezed my brother-in-law's '93 Bronco thru inspection. I held it at ~2000RPM while waiting in line (for ~30min

), but it might have passed anyway. I just didn't want to find out.

You shouldn't let them test it within 10 min of starting it. That'll make sure it's fully warmed up AND in closed-loop mode.

Mar 4, 2003 | 01:18 AM

tetraruby

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Failed State Emissions Inspection !!! Doh!!!

Don't forget to change the oil too. A fresh change can work wonders for an emissions test.

Mar 4, 2003 | 11:41 AM

seebeew

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From: Long Island, New York

Failed State Emissions Inspection !!! Doh!!!

Here was my results:
My Truck/Legal Limit

HC:
1.95/1.80 gpm

CO:
42.47/40.00 gpm

NOx:
.94/3.50 gpm

Im going to change the o2 sensor and do a light tune up. I hope that does it.
Thanks for the info