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Question for anyone with mechanical knowledge.
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| Transporter |
I have this old car 92 Chevrolet Cavalier 3.1L V6.
Went to pass the drive clean and failed.
Since the exhaust was all original and needed to be done, I had a new front to end exhaust put in (new CAT converter also).
Then had a tuneup....plugs, wires (which were originals also), throttle body cleaning, belts etc etc.
Did the test again and the bitch failed again ( yes i know it's an old piece of car but it doesn't burn oil and it runs good).
The I replaced the oxygen senson and the temperature senson.
STILL FAILED !!!!
Took it in to the dealership and they hooked it up to a diagnostics computer and they found nothing.
WTF is going on ???:whip: :whip: :whip: :whip: :whip: |
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| Orbax |
| how badly was it failing? |
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| Transporter |
Sorry I should have mentioned. Everything else is great except the "no" it is double what it should be.
I thought it might be the advance ignition but the mechanic said it is not.Also had the EGR vavle looked at and that is working ok. |
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| Orbax |
| weird. you did everything right. The only thing I can think of is run it to near empty, fill it up with premium, drive it arond for another 50 miles or so then take it to be tested. Cuz...thats friggin weird and I have no idea why it would run like that. |
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| Transporter |
I know :sadgreen: :sadgreen: even my mechanic said he hasn't seen anything like that before. He doesn't know why. His only suggestion was to open up the engine and see if there is carbon deposits inside.
NOT!!.. not gonna spend any money on that especially when the car runs great. maybe I'll just pay the penalty and drive her till the engine falls out. |
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| Orbax |
| go to your local highschool that has an auto shop. ask if you they want to use your car as a "project car" and try to diagnose it. They should have an emission analyzer, ours did. |
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| Vaedyn |
Are you getting it tested after taking the car for a drive? Definitely take the car for a long spin before getting it tested. Get the engine up to normal operating temperature before getting it tested.
Sam |
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| getfoul |
I am assuming you arent American because you are referring to it as "drive clean" instead of emissions. If you could post up your HC O2 CO and NOX numbers for idle and cruise. Pass and fail.
The EGR system is the onyl one that deals with reducing NOX emissions.
NOX is produced when you have temperatures in the cylinder combustion chamber exceding 2500° F To lower the combustion temperatures they needed an inert gas that would occupy space but not burn so they decided that exhaust gas would work best. AKA EGR *Exhaust gas recirculation* It injects a little bit of exhaust gas back into the intake manifold. Thus lowering temps and reducing the oxides of nitrogen in your exhaust emissions.
Ok now that that littlelesson is over. Did you have your full EGR system checked? the tubing and all teh other components? If they are working properly then the NOX number should be fairly low, around 40 ppm.
ALSO if you are American, if your mechanic is a State Emissions certified tech he can authorize a waiver for your car, all he has to do is talk to the state EPA board advisor, and most likely they will figure out a way to fix it. If not there is the 150 dollar rule and you can be issued a waiver on that premise.
wow, the state emissions certification is finally coming in handy :rolleyes: |
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| 3jaz |
adjust the stoichiometric ratio (air-to-fuel ratio.. pass the test .. then change it back
have you done any engine mods ?
could you fail the test due to engine oil buring ? |
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| Transporter |
| Thnx getfoul ... I didn't know that ... I will have the EGR looked at again .. Thnx again :gsmile: :gsmile: :gsmile: :gsmile: |
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| getfoul |
| quote: | Originally posted by 3jaz
adjust the stoichiometric ratio (air-to-fuel ratio.. pass the test .. then change it back
have you done any engine mods ?
could you fail the test due to engine oil buring ? |
NoX would be low if he was burning oil, that would lower the combustion temp.
If it tailpipes within the legal limits, then you would be fine. If it's OBD2 and you have a code for anything you fail immediatly. |
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