fail smog in ca..need a catalytic converter

[mr.vang]

delete. thanks

[jlevie]

A failure to pass emissions testing could be the catalytic converter, or it could be an engine that isn't running properly. The first action, unless you have proof the catalytic converter is bad, would be to make sure that the engine is running like it is supposed to.

[mr.vang]

A failure to pass emissions testing could be the catalytic converter, or it could be an engine that isn't running properly. The first action, unless you have proof the catalytic converter is bad, would be to make sure that the engine is running like it is supposed to.

idle like when it was new, runs like a champ, start everytime,doesn't burn any oil..the only things i'm worry about is the cat or the modif mustang o2 sensor..plus its a 20 yrs old cat, so it doesn't hurt to replace it.i'm going to seafoam it and change the spark plug..i also get a free re-test so hoping it'll pass with the cat replace

[castros]

I suggest that you buy new O2 plug and play type wont run no more than 120.

[mr.vang]

I suggest that you buy new O2 plug and play type wont run no more than 120.

i just bought the car last month and was told it was a mustang o2 instead of a oem..just need to smog it so i can register it..so can that be the cause...

[BenMGP]

I just went through the same thing. I ended up having to buy a cat. I only paid $250 total for the cat, installation, and smog cert.

If you o2 is bad, they should be able to tell you before hand. Most charge a diagnostics fee.

[blocke]

Did they tell you why you failed? Post up a scan of your test results sheet.