I'm down to one last pesky code after getting this 96 SS a year ago with 7 codes on it!
Looking for any ideas where to go. I get a P0133 code now. Car has mid tube Pacesetters, Magnaflow cats all put on this summer and no leaks that can be found in the exhaust system. Car is stock other than the exhaust that I know of but was rebuilt before I owned car about 15k miles ago. The sensor reads low but only at ide. I installed a new before cat sensor today thinking that must be it and no luck. So I'm thinking wiring problem next and gonna start to trace it down or do you think it could be PCM issue? I'm pretty new at this stuff so maybe I'm overlooking something or someone has some other ideas to try.
Thanks in advance.

 

The PCM is complaining that the O2 sensor is not switching voltage at too slow a rate (lazy sensor). If you only changed one sensor, you need to change the other side also. Your car has 2 cats and 2 upstream sensors, and 2 downstream sensors.

 

P0133 Heated Oxygen Sensor (HO2S) slow response Bank 1 Sensor 1 Sensor 1 = before cat
so just changing the one sensor for this code might not fix even though the other 3 don't trigger?
I was also wondering about an injector or lifter causing it since it's only one side.

 

Look at all upstream sensors with a scanner & see if the voltage constantly varies. Steady voltage = bad sensor. Downstream sensors show steady voltage if cat is good, and follow upstream sensor voltage if cat is bad.

 

Remember that the code shows not only the sensor itself but the related wiring involved. Check to make sure that you do not have any damaged wiring before you spend more money on new sensors.

Bank 1 is the driver's side BTW. Another thing you may want to do is swap left and right sensors and see if the problem moves. If so then it is a bad sensor. if not then it is the headers and or wiring.

Make sure you clear the codes with a scanner, OBDII does not always auto clear codes right away. Most OBDII computers require 50+ good test cycles before it will reset the CEL and not all systems are always tested. O2 Systems have like 4 tests that they need to pass and different driving conditions will engauge different tests depending on what the computer decides to do.

Massey

 

Thanks, some good ideas here!