B-fore I buy a used CAT: want to pass smog only
 

Guys, gutted my clogged main and secondary CATs a yr ago and now its time to get it smogged(CA).

Want to just pass the smog test and am looking at buying a used CAT. A few questions.

1. Do I need to replace both Main & secondary or will replacing Main alone allow me to pass?

2. How can I make sure that the used CAT I'm buying isn't clogged? Can you pass a light through them if they're still good?

3. Have read a few threads on "tricking" the test. Not really following how this works. Any suggestions?

Thanks

Need some help....anybody?

pretty sure that you only need the main cat if it is not burned out yet. Not sure on how to check to see if its still good or not. About tricking the test people have tried running injector cleaner through their engine or methanol in their tank. Not sure about the methanol to gasoline ratio though. Do a search. Also before testing make sure your engine is hot and try to keep it warm until they begin the test.

hmm...where you gonna get a used cat? sale of used catalytic converters is illegal in CA. junkyards won't sellem to you. it's usually posed at the front.

wow I didnt know that about selling used cats in cali

it depends how clean your car runs. i passed 4/6 with a new cat. previously had failed 6/6. thats a perfect score! whats your mpg? be sure to buy a 3 way cat if you get a new one. then get tested, fail, post your results, then people can make more recommendations. and stop punching cats.