Failed emissions test

[deepsquat]

My wife has an old beater car for a backup vehicle . It failed the emissions test Car a 88 dodge colt vista ..Fuel injected. passed on all levels except the cruise HC emissions ...pass was 160 ppm and she scored a 180 .
now the weird part ..I changed the plugs ( burns oil like there is no tomorrow) and clean the throtle body with a seafoam soak ..now the HC ppm is at 200!
What the heck caused this ? I figured sense the car barely failed plugs and an oil cjhange should have done it ..but noooo!v
Any opinions ?

 

[Virtuoso]

How old is the O2 sensor? Make sure the car is up to good temp too before the test.

 

[brianl703]

Is the ignition timing correct?

Maybe the injectors need to be cleaned with some fuel injector cleaner?

 

[ediamiam]

What kind of shape is your catalytic converter in ? They don't last forever.

 

[Eddie]

Had the same problem with an old volvo. We put in a bottle of Techron FUEL SYSTEM CLEANER. Took it out for a 25 mile highway run at ~65 mph. finished up most of the rmaining gas and it passed. You could try that. ed

 

[Matt_S]

If the car burns oil, I'd tend to agree with ediamiam. Converter. If you want to keep it, you may need to replace it. Perhaps there's a way to clean it out that might help you, but I couldn't begin to tell you how.

 

[deepsquat]

Thanks guys...I had thought of the timing and O2 saensor ...how about valve adjustment ? ...as fot he cat ...too$$$ would cost more then the car is worth

 

[Matt_S]

If the valves were that far out of adjustment, the engine would be making a helluva racket. If that's the case, though, get them adjusted. Thing is, I'm not sure if this car has solid lifters or not, so they may or may not be adjustable as far as I know. I kinda' doubt that valves are your problem, though.

You might try a double dose of a good, strong fuel system cleaner, like Redline SI-1. In the tech info , they state "The detergents used survive the combustion process and clean the PCV valve and the EGR port as well as cleaning deposits in the combustion chamber." Perhaps this might help you. You can get SI-1 at Advance Auto and at several web sites.

 

[patel]

Try BG 44K. Go to GM dealer. You will be fine for couple of years.

 

[MarkC]

My wife's 1993 Mitsubishi failed last year. I changed the oil, the plugs, wires, put in a can of something 'snakey', ran it down I-405 for 20 minutes, then took it for a retest and it passed easily.

 

[Gary Allan]

You didn't mention any operational problems. Nor did you say that the plugs were fouled. You're getting too much unburned fuel at cruise.

This also leads me to believe that the O2 sensor is lazy. You should be in closed loop at cruise and everything should balance out fine. I'm sure that you have a metered orifice for a CCV/PCV ..make sure that you dose that port with ample amounts of cleaner since it typically only sees one runner/cylinder.