make sure to have pretest first. If it will not pass the charge is about $15.00. If it fails you have to repair it at another shop then have it retested at a third test only shop. Also if it tests too high you are a gross polluter and you will have to pass smog every year for something like 4 years. I believe as long as the leak is downstream of the cat you should be okay. But, the exhaust probe has too see enough heat to work. If too much leaks out it will not register and you will not pass. If people do not turn their head when you drive buy the leak is probably not enough to worry about. Also if any trouble codes set while on the dyno it will not pass but, the check engine light must come on when you turn the key.

Here are some web sites to check out for California smog 2 checks

Bill D. Modesto Ca Smog check 2 land.

http://www.smogcheck.ca.gov/smogweb/

http://www.smogcheck.ca.gov/smogweb/

http://www.smogcheck.ca.gov/smogweb/