Passing Smog Test

[philipk65]

Hi!, I have had great advice on this forum and hope someone can help me out!

I have a '91 S-10 4.3 L. I'm live in California and it won't pass the emissions test. The only category it fails is the "NO - 15 mph" test.

Before I throw money at parts I don't need. What is the cause for the truck to fail the 15 mph NO test?

O2 sensor, cat. converter, EGR. could all be a cause, but if try to test each one the best I could.

What about the EGR vacuum soleniod?

Any advice would be great! Thanks Kevin

[MT-2500]

Originally Posted by philipk65

Hi!, I have had great advice on this forum and hope someone can help me out!

I have a '91 S-10 4.3 L. I'm live in California and it won't pass the emissions test. The only category it fails is the "NO - 15 mph" test.

Before I throw money at parts I don't need. What is the cause for the truck to fail the 15 mph NO test?

O2 sensor, cat. converter, EGR. could all be a cause, but if try to test each one the best I could.

What about the EGR vacuum soleniod?

Any advice would be great! Thanks Kevin

Ask the inspection station for your test readings.
And ask them what all is in the 15 MPH test.