Failed emission test....

[greekguy7]

My 1987 Honda Accord LXi failed emission test for high CO. The spec is 30.0 and it failed at 33.3.

Without throwing replacement parts at it blindly, what would you say are the biggest causes for this? Thanks!!

[1988starter]

Check your timing plugs wires PCV valve ect and make sure your car is fully warmed up before you go. Also there is this stuff I have heard about called gaurenty to pass or something like that you can get at an auto parts store. A couple guys on here say it works.

[danronian]

I failed my emissions test a few months after I bought the car and they one spark plug wire had a break in it and the plug didn't light all the time. I would suggest checking if the plugs are firing before doing anything else, and if your plugs are old, replace them, it cant hurt anything and is a real cheap fix.

[njpeter]

while you're spraying..hit the hoses too..if the idel speeds up you've got an air leak..and ANY leak in any hose means you have a good chance to fail. I'll agree on plugs and wires..cheap way not to hit the line 3 or 4 times..not to mention getting tickets ( and in NJ, an uninspected over 30 day fine is $150)

[Aarie$$oul]

I also failed my emissions test for my 86 accord. the co was too high. I'm taking it back next week to get reinspected. I've had some things adjusted and replaced. my question is for nj residents...say u go back with ur reciepts and the form filled out saying what you got fixed and where you got it fixed, but you fail again...What happens then? I heard depending on how much you spent to get it fixed the first time , they give you a waiver so you'll get ur pass sticker.

[Vinny]

I've heard everything from regular tune-ups(plugs, wires, air filter, fuel filter PCV valve), some people say use that guaranteed to pass crap, others say lean your fuel mixture out. I had a few friends of mine that work in places that do inspections/emmission testing In Dallas tell people to change there oil, (I know but it seems to work) or I've even known people to put alchohol in there tank (supposedly helps it burn cleaner)

[Aarie$$oul]

actually i called the inspection center and the lady told me with CO failures usually an oil change will correct it and luckily i just got one the other day! I've heard about the alcohol in the tank but i think they said it wasn't a good idea or that it produces other other emissions.

[Mac]

High CO is usually dirty air filter, dirty oil, or bad pcv valve.

[Aarie$$oul]

Thanx Mac. I got a new air filter and changed oil. I went and took my reinspection...and failed again! This time only for one thing....

High idle!

That sucks. I'm going to a auto repair place that is certified to give inspections and just pay for it and get the repairs i need. Here were my emission readings. the passing requirements are in parenthesis

First failure...
Nox-689 (1438)
hc-96 (187)
co-2.98 (1.05)

New readings -passed
Nox-1407
hc-22
co-0.18


My question now is why would everything else go down but my NOx shoot up like that?