I would not say this code has zero affect on anything, it could possibly lead you to the root of your problem. Actually the P1133 code means that the voltage fluctuations after the motor has gone into closed-loop is not switching, or not switching fast enough. O2 sensor voltage should constantly be changing from somewhere under 500 mv to somewhere above 500 mv. This could possibly be due to a very lean or very rich fuel mixture, bad o2 sensor, too high fuel pressure, etc, etc. Read the o2 sensor voltage while the car is running - that can indicate too lean or too rich.
