1997 Chevrolet Tahoe Q&A
1997 Chevrolet Tahoe Question: I changed 02 sensor (code po135) and check engine light still on.
Please understand that a parts house counter person is not a "service person". They sell parts, they are not auto technicians. This the manufacture's answer to your question. P0135 Heated Oxygen Sensor (Bank 1 Sensor 1) Heater Circuit Malfunction Possible Causes Setting Conditions •HO2S connector is damaged (check pins for damage, and for moisture) •HO2S heater ground circuit is open or has high resistance •HO2S heater Ignition circuit is open (test O2A fuse in fuse block) •HO2S heater element has failed •PCM has failed DTC P0101, P0102, P0103, P0106, P0107, P0108, P0112, P0113, P0116, P0117, P0118, P0121, P022, P0123, P0131, P0132, P0134, P0137, P0138, P0140, P0151, P0152, P0154, P0157, P0158, P0160, P0200, P0300, P0401, P0404, P0405, P0440, P0442, P0446, P0452, P0453, P1120, P1125, P1220, P1221, P1258, P1404, P1441, P1514, P1515, P1516, P1517 and P1518 not set; engine running, ECT and IAT sensors less than 122ºF and within 14.5ºF at startup, HO2S signal from 425-475 mv right after startup, Intrusive and Scan Tool tests not enabled, MAF signal less than 25 g/sec, and the PCM detected the HO2S signal remained within 150 mv of startup HO2S signal for a predetermined amount of time based on the ECT and airflow inputs. This code sets in 2 Trip(s). This code will turn on the MIL (Malfunction Indicator Lamp) - PARTS GUY
The Bank 1 Sensor 1 is located on the side of the engine with cylinder #1 before the catalytic converter. The most frequent fix is to replace the sensor. It's apparently not hard to remove and screw in a new sensor, but the location of this one is a bear to get to. That means really difficult. One way to avoid the hassle is to take it to a mechanic who knows how and has the right tools. Hope this helps some. - Ken Sylvester
After the o2 was replaced did you clear the codes and then the light came back on? - pushrod