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Failed inspection


SrMichi

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here's a little guide i came up with after lots of reading on teh webz...

 

Too much timing causes high NOX and high HC

Too lean causes high NOX and high HC

Too rich causes high HC and high CO and low NOX

EGR helps remove NOX and cools exhaust valves

EGR can increase HC/CO(diesel only?)

CCP/PCV is to reduce atmospheric HC by burning it in the motor...

 

judging by that, i'm guessing you have E10 fuel mandatory where you're at? that would cause the lean issue that can cause high HC. especially since at idle, depending on the mask, the ECM will ignore the O2...

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So what do I do to correct it?

 

find fuel that doesn't have ethanol in it? or find a way to remove/nullify it?

 

other than that, if you don't have tuning capability, i don't know what to tell you.

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Yeah i drove like 15 miles highway to get to the inspection station. But I have notice that the temp gauge never really gets to the middle it just stays between the quater and half section.

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Try dumping a can of Seafoam into it before you go get it re-tested. That might help, or it might not. Either way it won't hurt anything.

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So the gas is causing me to fail inspection? :shrug:

 

not really. it's GM's awesome idea of basing idle fueling off of IAC counts instead of VE numbers and the O2 sensor at idle(you can switch it to act normally if you can tune it though)... but since the O2 reading is so high, and fuel with ethanol in it burns leaner than straight gasoline, the gas isn't helping...

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get a few gallons of race fuel?

 

assuming it doesn't have some funky oxygenate in it that messes with the cat's ability to keep CO and HC down, that MAY be the way to go...

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How's the idle on that car? A small misfire, vacuum leak, etc. can cause the HC to be too high at idle. It also wouldn't hurt to try to measure the temp of the engine since you mentioned the gauge seems to indicate low. If it really is too cold, that can cause it as well.

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Have you checked to make sure vacuum routing is proper, the EGR is not borked from mileage/sitting, the oxygen sensor is clean and working, spark plugs are gapped properly and working right. It didn't seem like your readings were horribly off, so maybe just getting the routine maintenance all covered and try again. Could there have been old gas in the tank?

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I don't think they check for chips. I'll change thermostat and check vacuum lines. All of the routine maintenance was done 15k miles ago if not less. About he old fuel I have filled up once already Ill try dumping some sea foam in the remaining fuel. If everything checks out and it still fails I guess I'll try sunoco.

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Have you checked to make sure vacuum routing is proper, the EGR is not borked from mileage/sitting, the oxygen sensor is clean and working, spark plugs are gapped properly and working right. It didn't seem like your readings were horribly off, so maybe just getting the routine maintenance all covered and try again. Could there have been old gas in the tank?

 

stuck shut EGR would show up as high NoX(but i actually don't see that listed...), but it's not commanded on at idle anyways.

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