DOES the Nissan Altima line with SR20DE have a cold start valve ?
Oddly, it does not come with an 02 sensor like the Serena's with the same
The SR20DE has a cold start valve. If not, it would not be able to start.
You may not be looking for it in the right place.
Similarly, there is an 02 sensor but it may not be in the same location
as the Serena.
The 02 sensor is usually fitted either at the top of the exhaust manifold
or underneath the car next to the catalytic convertor.
Without the 02 sensor, the car will not run properly.