Does anyone know when they started to put dual cats on the LT1's? I thought it was in 96 with the OBD II setup. I just bought a 95 Z28 with a build date of 04/95 and it has OBD I according to the emissions sticker, but it has dual cats. It is an original exhaust from mainfolds to tips. Is it possible this car came with dual cats or did someone change the exhaust from another 96?

Thanks,
Curt

 

From what I understand the early '95s had one cat, while the later '95s and the '96s had two cats. I had one cat on my '95 but I took it off.

 

04/95 is a very late build, so it probably came that way.

 

Thanks for the info.

 

Is it an automatic and have RPO code NB6?

 

California spec'd 1995 A4's had dual cats. My California spec'd 1995 M6 (also an early build date of 8/94) is a single cat.

 

No. All 95's are single cat cars, except the CA emissions A4 cars, as stated in the post immediately above. The CA emissions A4's are dual cat. The M6 cars are all the same "50-state" model and did not require a CA emissions package.

 

Thanks guys. I will look for RPO code NB6. I know the car has been titled in Massachusetts since new. I noticed on the emissions sticker it says California complient.

 

Just checked the RPO and it has the NB6. I don't understand why a car that went to Massachusetts was California emissions legal. Thanks for the replies.

 

Some time in the mid 90s GM went 50 state legal with all it's cars. Just easier that way I guess.

Re'

 

NB6. That's why it has two cats. Might have been a dealer trade out.