Depending on the State you reside, you should check with the Dept of Transportation. I know in my State, if the car is no longer registered in California, then only federal standards apply. This would include a Universal catalytic Converter in most cases. However, If the car is licensed in California even though you are no longer in their domain, the Ca. Emissions standards will apply. So, if that's the case, you are in a catch 22 if you need to pass an emissions test, unless you aquire a waiver from the DOT allowing federal standards replacement on a CA. Licensed vehicle, so that it can actually pass a test and be licensed in the new State. (I am only using my State requirements as this guideline). Also, if relocating outside of the USA, you may obtain a DOT waiver to have the emissions removed if you are going to use leaded fuel outside the country.
Good luck, Check it out with your DOT.
If federal compliance is the standard, you will save a ton of cash using the more inexpensive replacement converter. (Some still require duel in-line converters depending on the model and drivetrain, or a duel in whick is also expensive, but still about half of a dealer replacement.
Monday, March 17th, 2008 AT 12:07 PM