1997 Friebird Code interpetation

[JMAC71]

HEy Guys,
I have a 1997 Firebird with a 3.8 liter V6. Service engine light came on and it shows a computer code that reads :Catalyst system effiency below thresold: What does this mean? And what needs to be replaced. I am guessing oxygen sensor or Catylitic converter? Any ideas will be greatly appreciated.

Thanks,
JMAC

[FormulaLT1]

That code can only come from a rear O2 sensor. So I am going to suggest replacing that O2 bank first and then clear the code. If it comes back you may be in need of a new cat. Good luck. You may also be able to swap the o2 to one of the other locations and see if the code follows it.

John

[Turbo V6 Camaro]

your cat converter is bad or that O2 sensor is bad

mostlikey the cat

[Turbo V6 Camaro]

Originally Posted by FormulaLT1

That code can only come from a rear O2 sensor. So I am going to suggest replacing that O2 bank first and then clear the code. If it comes back you may be in need of a new cat. Good luck. You may also be able to swap the o2 to one of the other locations and see if the code follows it.

John

cant do that on the 1997 v6's the 2 in the headers are used for fueling and one before and after the cat.....

90% chance its the Cat, very common to go bad in these cars