994door

I'm swapping a 96 gsr into my 99 civic. I'm keeping it obd2 so it requires a second o2 sensor. on the stock motor the catalytic converter is attached to the manifold so there isnt one under the car. do i need to put a catalytic converter under the car for the new motor?

Slurp56

Yup.

B18CivicEJ8

You will need the cat back exhaust section of a 99 Civic EX for it to work. I would also recommend you get a 99 Civic EX engine harness. This will save you a few hours because you only have to add in 1 wire for the Intake Air Bypass valve.

994door

thanks... does it matter what car the cat is for because i have a new cat for my 91 integra but i sold the car before i could install it? so i need get a catback for a 4 door ex the attach the cat to that?


Modified by 994door at 9:53 PM 4/24/2007

B18CivicEJ8

Yes, you need a cat from a 99 Civic EX because that already has the secondary O2 sensor bung tapped into the cat. The 91 integra cat will not have this sensor which will defeat the purpose of your original question. So you need the cat and entire exhaust section of a 99 Civic EX, unless you plan on adding an aftermarket cat-back exhaust. If you go that route, then all you need is the cat from the 99 EX.

994door

does the jdm gsr ecu require a second o2 sensor?