Having problems with your 1999 Chevrolet Blazer ?
Failed emissions test.is int.manifold gasket set replacment & plenum o ring & gasket necessary.co% limit .70,was .82;hc ppm limit 150,was151.
Does it have a vacuum leak? If it was that bad it should have thrown a code. That being said the first thing I do with a vehicle that fails emissions is to replace the o2 sensor. o2 sensors start wearing out the day they are put in. Generally I like to replace mine once a year though I know that is a bit of overkill. It does make sure the system is running topnotch. keep in mind my vehicle only has one o2 sensor.
Repair Help & Product Troubleshooting for 1999 Chevrolet Blazer
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