Fail Emission - CO too high – help
 

OK, fail the emission, * CO is limit to 4.5 at idle, but she got 6.65, here’s what I’ve done in preparation for that test:

• Change oil & filter
• Clean TB, PCV, air filter and spark plug
• Change distributor cap and rotor
• I run through the freeway before the test, so she completely warm up.

To do list:

• Change the plug to NGK iridium
• Put some high octane gas + octane booster additive
• Change the PCV

What else I need to do to get it pass? Thank you for any tip(s)

How many miles are on your car? When did you last change the spark plugs? Did you use the OEM plugs suggested in the owner's manual?

210k KM, i don't remember changing them, i just clean then check the gap. she has 180k when i bought it in 2010, but last year it passed the test. nway maybe she need new plugs, but it better to get iridium or just the ordinary copper?

just a quick update: i passed the test yesterday, i didn't see the actual numbers though. this is what i done:

change the plugs and air filter
i pour 1 lit of denature alcohol in 1/4 tank
2 small bot of STP octane booster
1 bot of STP full fuel system cleaner

i know i desperate to pass, :)
i dilute it with a full tank of good gasoline after i passed yesterday, i don't want to destroy any fuel system component from the additive that i put on her...

The OEM plugs should be changed every 24K miles, so you were past due. The new plugs likely got your car through the emissions test.

^^^ we'll remember different things, thanks for posting back up.

This is what I'll remember -

I would tend to believe the plugs making it pass more than the other things.

i agree! but i think the additives (specially the denature alcohol) + good fuel contribute to lower my CO and cleaning up my combustion. i will repeat this method next year :)

Oops, here we go again, failed the test yesterday! Another high CO, now its 7.8, limit of 4.5

This what happen, when I reach the testing center there was a very long queue, I've been in the line for more or less an hour I think, and because I only have lil lower than ¼ tank, I turn off the engine three or four time for about 5 minute or so, you think turning the engine off cause my test to high CO?

Done before the test:

Change the oil
Clean PCV, air filter, TB
Add 1 lit of denature alcohol in ¼ tank
I have the old spark plug and rotor, I just clean them with sand paper.

Things probably doing before the re-test and I need your advise

New spark plug
Have read somewhere that acetone and solvent help reduce CO
Remove the stock air filter before the test.
High octane fuel or octane booster additive

Thank you in advance.

another to do list, addition form the list above

AC, should it be on or off? - please advise