How do they do emissions test on 7.3's here in Tennessee? I heard from a buddy of mine said that they plug something up to your truck and they check from there. Is that true? Or is there a completely different procedure?

 

Not sure how standard the testing is but here's the process for me in Southern California:

- Shop plugs into my OBDII port and the computer (which is hooked directly to the CA DMV) does a diagnostics check.
- Technician inspects vehicle to make sure parts are OEM, CARB (California Air Resources Board) certified, or in compliance with the instructions (e.g. 6637 air filter).
- Technician starts truck and aligns rear-view mirror to see exhaust exiting tailpipe. He/she revs the engine a couple of times then performs the "snap test":
- Technician quickly revs the engine to about 3000rpm three times and checks for "excessive" smoke coming from your tailpipe.
- Test over. Pay $50.

Besides hooking up to your OBDII port, the rest of the test is subjective. Some shops have different interpretations of the rules (and specific things they look for) so what may pass at one shop may fail at another.

 

Wow that all sounds like no fun. We don't have emissions testing here in Minnesota. Although given the current political climate I'm sure it's something I have to look forward too.

 

No emissions here in PA either. That country known as Kalifornia has their own rules that don't apply anywhere else. So far the only other state that I have heard of (IIRC) that checks emissions on these things is CO.

 

here in AZ they use mirrors with a beam of light to check opacity. I like to call it smoke and mirrors

 

Well at least in my part of CA. it is just a visual to check to verify that everything appears stock. Last time I had to do it at least. I have an AFE air filter and intake system but they are CARB compliant. I do carry the documentation in the glove box just in case!