1995 Metro 1.0 leter won't pass emmissions.

1995 Metro 1.0 leter won't pass emmissions It fails on HC on Idle by 141ppm I've replaced plugs wires cap rotor O2 sensor air filter what's next?

Did you change the oil?

Dirty oil will cause the hydrocarbons to double what they normally read, and even slightly used oil will cause the #s to go way up.

Did you change the oil?

Dirty oil will cause the hydrocarbons to double what they normally read, and even slightly used oil will cause the #s to go way up.

The oil & filter was changed about 600-800 miles ago. It has a slight rough idle also.

I would definitely change the oil then.

As for the rough idle, I've read that just about everyone experiences that same thing. I know every one I drove before I bought mine did, as does the one I have. I think it's just the way they're built.

As fars as hydrocarbons go, the big things would be the air filter, the oil, and then the air/fuel mixture.

I have also found that after about ten years the catalytic converter fails. usually this will affect the NO readings, however it also can affect HC's and kill your oxygen sensor. there are acouple of outfits in California that make direct fit cats (they don't) they usually need a little modifying to fit. but for around 120$ + shipping it might just solve your problem. Also how many miles do you have on the car? worn rings will cause high HC readings. Just my 2 cents

You should also take the EGR valve off and check to see if it is all clogged up.

My 93 1.0 geo would not pass the idle emissions HC test. Had a reading of 220ppm over the limit, i have 182,000 miles on the engine. I ran a tankfull of higher octane gas and guarantee to pass emissions cleaner in the fuel . when i ran that out, i changed the o2 sensor and catalytic converter from auto zone. Put reg. gas in the tank and back for the emission test and passed with flying colors . HC at idle 9 ppm. all other readings normal. :smile: