Does the stock 97 Hatch (DX) have only the cat in the exhaust manifold? Or is there a secondary. I noticed my brother in laws coupe has two cats. My car failed smog due to high NOX and i'm wondering if this could be the problem. I seafoamed the engine, changed the plugs, wires, oil. But have yet to try smogging again.

 

Ttt, help me out!

 

You only have one cat.
Seafaom is junk in my opinon.