Been having a ongoing problem with this P0134 code(B1,S1). The first time i got this code along with a P0130 i replaced the B1S1 sensor as noted. Got the code reset but it came back soon after. I did have some exhaust leaks that were patched up. Its seems as if the leaks are fixed because i don't hear them anymore like before. Still getting P0134. Something related to the circuit activity. Anyone know where the fuse related to that 02 sensor is located? I did a voltage check for the 02 sensor at the connector inside the car and all checked out normal(voltage,ohm). Reset and still code pops up. Gas mileage is slightly down also. What am i missing? Overlooked leak, faulty new sensor? I'm at a loss. I was also wondering how could leaks after the main cats cause a pre-cat code if it is exhaust leak related?

 

I guess no one has a clue.

 

That code relates to no activity on the circuit...

What are O2 voltages from the sensor? You can look at live data in a scan tool or measure voltage with a voltmeter, either will work... If measuring with a voltmeter, try at the sensor plug and the ecu...

Assuming the o2 sensor is in working order and the wiring is correct, a ecu is your next course of action...

 

Will do. Any idea where the ECU is on the 05 LS430? Really hoping its not the ECU. $$$$

 

Pretty sure its behind the headlight on the drivers side...

 

Well i checked the voltages at the plug inside the car near the drivers right knee. With the car running, the black wires(heater) read 12v+ and the other wires read between 800-900mV. Read these voltages on both sides of the plug. Ive located a ECU in the engine bay behind the drivers side headlight. Not sure if its the correct one since this car has so many ecu's. Its labeled "Engine Control" so im assuming its it. Now im not sure where to start here since i don't have any schematics. I do know the ECU-side wire colors of the 02 sensor(brown w/silver dots and dark green w/silver dots) but didn't see them at that ECU. Not sure where to go from here.

 

........Bump!

 

O2 heater circuit problems have a separate code that specifically states a heater circuit problem. You can't read the O2 sensor signals with a multi-meter because it produces a waveform. If you have a half decent scan tool, you can read the engine live data that the ecu is seeing. This will tell you the a/f ratio of the b1s1 that the ecu sees.

Correct me if I'm wrong, but I believe that code is a 1 trip, continuous monitor. Which means if it sees no signal once, it will throw up the MIL. Even if it sees the signal again, the code will remain until the car goes through enough warm-up cycles. If that's the case, you should look for pinched wires or loose connectors, anything that would cause the ecu to lose signal voltage intermittently.

 

This isn't completely true. O2 sensor signals are not waveform by design - they are a varying voltage, in which roughly .5 volts = stoichiometric, or 14.7:1 AFR, anything richer than 14.7:1 and voltage increases up to about .94 or .95 volts, with 1 volt max, and the opposite is also true, closer to 0 volts as the AFR is leaner. Unfortunately with a stock narrowband sensor, you only truly get rich, stoich or lean - no true AFR...

A properly operating o2 sensor and an engine that runs well, will have a waveform like voltage response, but if it is lean, it will stay low voltage and vice versa...

 

That is true, thank you for the correction. However, with the induced waveform, it's still not very feasible to read the outputs with a multi-meter, at least for me I haven't been very successful with it.

 

So even tho i got an exceptable reading the sensor with the multi meter, there's still possiblity that somethings wrong with it? Gonna try and check out the wiring this week end.

 

In my opinion, the multimeter reading is not accurate enough. The rate at which the multimeter reads and dislay data is a lot less than the ecu. A scan tool would show you exactly what the ecu is seeing, which is only to determine the possible problems. By seeing how the ecu perceives the sensor is acting, you can have a place to start.

I would look at that data and then start wiggling wires to see if anything changes. It is possible to wiggle it just right to cause high resistance or an open long enough to produce that code if that is indeed what the source of the issue is.

On a side note, if you have a friend who works at a dealership and get them to hook up the TechStream to your car, there will be an associated freeze frame with the code. This will show you the parameters leading up to, during, and after the code was set (in fractions of a second).

 

You can do the wiggle test with the multi-meter also. Just back probe the appropriate wires at the ecu (using a connector/pin diagram) and start wiggling wires while looking at the signal voltage.

 

I have a 2003 gs430 and anytime you replaced a sensor look very careful for at the plug and wire because there usually a break in the shielding of the wire. I had to re do my wiring for my knock sensor a wiring after replacing both of them because the I kept getting the same codes.