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Discussion Starter #1
Well I am very close to throwing my 9c1 to the scrap-it program.. for the past month I have been trying to get my car through our emissions test. It is only failing the Hydrocarbons but is failing them badddd... I have replaced the cat/02 sensor/plugs/wires/egr valve checked for vacuum leaks and still my car is failing..

what else can I check for? and is there anyway to cheat the system? :D ...

thanks in advance.
 
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Discussion Starter #2
There are product that you can add to the gas that say "Guarenteed to pass emissons test" I normally don't believe in these type of products but having performed thousands of test when we had them here in Michigan I saw great results. Check with some local auto stores and see what they have.
Then when you get some time and money have it tested and find out the real problem.
 
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A high hydrocarbon count is indicative of the engine running too rich. Coud be a dirty air filter... if not, something else is telling the PCM to add more fuel than it should be getting. A vacuum leak would account for that, but you say you checked for those.

Can't say for sure, but something is amiss in the fuel control area. Is this an LO3 or LO5 TBI? Make sure the throttle body is snug and the gaskets aren't leaking.

When you are in the inspection lane, also keep the engine revving when you get close, to keep the cat temps up and reduce emissions as much as possible.

HTH
Steve
 
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Discussion Starter #4
man i am in love with thise board. i've failed the HC emission test here in dc but i passed the no and carbon one and wanted to find a easy way to past the test.
 
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Discussion Starter #5
A leak in the exhaust manifold can sometimes suck in fresh air past the o2 sensor, making the pcm think it is lean, and then add in a bit of fuel. I think that is the problem with my 95 DCM

Peter
 
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Discussion Starter #6
Thanks for the help everyone, finally got is passed today.. had to do some major tweaking.. (timing etc) but eventually found it's sweet spot.

I know what the problem was (well still has to be fixed) and BBODYGUY you hit the jack pot... had a crack right before the CAT that needs to be welded up.. well I think that is one of the major probs, also my engine is getting tired (burning abit of oil now) ...

oh well.. at least I can finally insure it!

:D
 
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Discussion Starter #7
Just a note. High HC readings by themselves are normally indicative of unburned Hydrocarbons (duh) which is typically misfire, oil burning, timing too high and the like. Long over lap cams are bad for this cause not matter how well the engine management does its job, when both valves are open for extended time unburned fuel and free oxygen go out the pipes. The O2 sensor sees the O2 and fattens up making things even worse. This is also why any upstream air leaks are so detrimental. A rich mixture will show as high CO and somewhat elevated HC. Granted if the mixture is unreal fat you will have unburned fuel out the pipes that will show as high HC. Winding the timing back a mile will lower HC but is not a long-term fix. You think Aircare in the lower mainland is fun for owners? Try being one of us poor saps trying to fix cars for people and keep the customer happy and our REI high so we don't get in trouble with Aircare management. Every time we have a less than stellar result it goes down as a little black mark in our tech record. Gerry
 
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Discussion Starter #8
Being a throttle body I would also check the injectors themselves, sometimes when they get older they can leak excess fuel into the engine. Also check the coolant sensor used for the computer, if they are a little off, it will throw everything out of whack.
 
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