Isn’t it illegal to tamper with the catalytic converter just to pass a smog test?


No, it is not. My recommended procedure is not tampering with the functioning of the catalytic converter. In most cases, the reason why an old CC fails a smog test is because the smog equipment is calibrated too sensitively. The CC is still good and still does its intended job of blocking pollutants from the vehicle’s exhaust, but unlike a brand new CC, it is no longer sensitive enough to pass a smog test. A really bad CC that has reached the end of its useful life will definitely fail a smog test no matter what kind of trickery or cheating you use.

Updated on April 13, 2018

Original Article:

How to Pass a Smog Test With an Old Catalytic Converter
By Daniel Mollat