P0135 3.4 silhouette

[riskman70]

Hello, new here and couldn't find anything that is exact to this situation so hope im not duplicating threads.

2002 Silhouette 3.4

Engine light came on and van was running rough, stalling at start up until warm etc, used code reader and got P0135 and P0135 S. Change B1S1 O2 sensor with a cheap replacement. Cleared codes. Van now runs fine but engine light came right back on again.

Cleared codes again to try and monitor when the engine light would light up during the drive cycle. It seems to light up when is it to running the HO2S system. (no engine light is on when HO2S is in "not ready" state).

I tested van harness volts with multimeter and got 11.2. (C&D on van harness connector) (Not sure if I tested the ground properly though)

I tested new O2 sensor resistance (A&B side opposite the harness connector) and got 6.2ohms.

Not sure where to go from here and need to pass emission test.

Had water problems in the past (leaking through both sides of the roof)

Any help would be appreciated.

Thanks

[Tech II]

That code is for the heated circuit of the sensor, however, it could be the other circuit too.....

Basically, you have two circuits(4 wires).....the heater circuit and the O2 sensor circuit.....on the heater circuit, you should read BAT voltage on initial startup....the other circuit, the O2 sensor circuit, should be sending back a bias voltage of around 450mv....then when the heater circuit has warmed the O2 sensor enough, it should start varying, based on oxygen content......

When the time it takes for the O2 sensor data to start varying, is too long on initial startup, this sets the code......

Not sure if you have a code reader or scanner, that can watch O2 data.....if data is ok, then either you have a bad sensor, bad connection to the sensor, or open in the heater circuit......if you were not receiving proper O2 data(let's say either one of the legs to the O2 sensor was open), then that would set another code....since it didn't, the problem is either in the heater circuit to the PCM somewhere or the PCM itself......