OK so first off I purchased this 99 civic ex for a pretty good deal
its in great shape but I noticed a couple things that I need to address

first thing I noticed is that it isnt the original engine Its a D16Y5 with auto tranny
The CEL is 67 I looked it up its a bad cat and I knew something was up because it gets about 24-26 MPG and I notice little black spots on the back of the car (white car) as if its running rich or something of that nature.
Ive reset the ecu several times and can drive about 15-20 miles before same code appears

So heres my quandry IM unsure what cat to get and would like to find a used one if possible

The exhaust is a 2 piece manifold NOT the type that Ive been finding where the car is hooked to the manifold in a vertical position ( I assume its the civic ex exhaust)
after the 2 piece manifold it comes to a small canister with what appears to be an O2 bung
this is located directly below whereabouts the shifter is then it goes for another couple feet and there is another canister.

So..... What model cat do I need and which one is the cat?

thanks bunches

 

Take pictures it's hard to tell exactly

 

The engine is running rich, so you need to fix that problem before you purchase an expensive cat.

What ECU?

Have you done an ignition system tune up?

 

p2p A92 ah thats the D16Y8 ecu

what ecu do I need?

and I havent done an ignition tune up Ron

first canister
http://imageshack.us/f/51/80b1.jpg/

second canister
http://img12.imageshack.us/img12/2289/z4m7.jpg

 

Do you have D16Y8 head on a D16Y5 block?

 

It is sitting the way it was purchased
not sure how to tell really

http://img708.imageshack.us/img708/2531/9qfv.jpg

 

How can I identify the head to see if its a Y5 or a Y8 head

 

Under the valve cover does it look like this

Y5


Or

Y8


Block ID

 

I have a D16y5 whats my next move to amend this issue

 

Buy a 99-00 D16Y8 head to replace the D16Y5 head currently on your engine.

Do you currently have a 99-00 D16Y8 IM?