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Showing results for tags 'Oxygen sensor'.
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There are oxygen sensors that control the fuel delivery and there are those that check catalytic converter function. I sometimes get the engine light turn on when it is cold, with codes that tell me that the heating is not working properly in the O2 sensors (PCM 0135 and 0155). Those codes are for the O2 sensors in the manifolds (one for each cylinder bank). I am now about to replace those two O2 sensors, and I have two questions: What is the difference between AFS109 and AFS125? Both have the following (identical) description on Rockauto: SENSOR,HTD OXY(POSN 1) IN EXH MANIFOLD/CROSSOVER. They have different prices. Is there any reason to replace the other two O2 sensors (one on each side of the catalytic converter)? Even if they were a bit "tired", that should still not effect engine performance in any way, correct? Only the two in the manifolds are involved in the closed-loop engine control, right?
As some of you know, I am about to change my O2 sensors (the two in the manifolds), since I occasionally get codes telling me that the heating is not working properly (PCM 0135 and 0155). I just checked some readings with my OBD link computer interface and read the following values: O2 Response Lean/Rich Transitions Time Bank 1 Sensor 1: 25 ms. O2 Response Lean/Rich Transitions Time Bank 2 Sensor 1: 83 ms. O2 Response Rich/Lean Transitions Time Bank 2 Sensor 1: 94 ms. I also meant to record the B1S1 R/L Transitions, but accidentally recorded the following isntead: O2 Response Rich/Lean Switches Bank 1 Sensor 1: 145. Does anyone know what that number means? If it means switches per second, then one switch would be less than 7 ms. Anyways, comparing Lean/Rich for B1S1 and B2S1 above it is clear that the Bank 2 sensor is slower than it could be. I also got the following reading, which I suppose are for the O2 sensor in front of the cat. conv. O2 Response Lean/Rich Transitions Time Bank 1 Sensor 2: 30 ms. O2 Response Rich/Lean Transitions Time Bank 1 Sensor 2: 44 ms. I do not worry very much about the last to values, since as far as I know that sensor is only involved in monitoring the efficiency of the catalytic converter. Since it is hence not involved in the feedback loop for engine control, its response time should not matter (other than probably setting a code if it got very slow). Is that correct? Is the O2 sensor just in front of the cat involved in the engine control in any way? Does anyone know what the normal switch times are for new O2 sensors? I will change the two sensors in the manifold/crossover either way, so I will find the answer to the last question, but I am unsure if there is any point in replacing the "third" sensor in front of the catalytic converter. /Jonas