My car just pulled up with code PO 133. I looked up the code list posted by desert a while back, but I have no idea what that means. does anyone know what that is in english? Primary HO2S Circuit Slow Response (Sensor 1)

 

Primary O2 sensor is the one in front. If it's an F22 (like your screen-name?) it's right therein the exhaust manifold.

Slow response is the way those sensors usually die. Poisoned by silicon or ??? If it was a 'no signal'error you might look at loose wiring, but the slow response error is probably a bad sensor.

 

The EX has the front O2 sensor on the connecting pipe right in front of the catalytic converter. Unless the change from OBD1 to OBD2 moved all of the O2 sensors on the exhaust manifold.

You'll have to jack up the car to replace the O2 sensor. I had to hold a torch on mine for about 5-10 minutes, then the sensor screwed right out.