Mechanics

PASSING EMISSIONS

GMC Other

My 1991 chevrolet camaro rs 305 5.0 is having trouble passing emissions I have changed oil, egr valve, fuel filter, smog/air pump and have no idea of what next hc is 251 high 256 low CO is 4.9 high and 5.47 lowwhats next? Also did tune up distributer cap and rotor plugs and wires
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Joshrs91
March 7, 2006.



Have check the catalitic converter?
That helps a lot to reduce the emissions.

Tiny
Fisherman
Mar 7, 2006.
Today changed catalytic converter reduced emissions a lot still not passing barely what do I do?

Tiny
Joshrs91
Mar 8, 2006.
Your check engine light is on?
How about your oxigen sensor?
Your tires size?
Stock size? Smaller? Bigger?

(The dynamometer test equipment is calibrated to the " stock" tire size. Over- or under-sized tires will alter the speed calculations performed by the test equipment and may prevent your vehicle from going through the test since the machine won't sense the correct speed for your vehicle's tire size)
those small details affect the test.

In what did your car fail?
Gross polluter?
Functional?
Visual?
Tailpipe?

Tiny
Fisherman
Mar 8, 2006.