Oxygen Sensor

[nicenic61]

Folks,

Me again, with the industry-standard worn out LS400 Mk4. This oxygen sensor error, 'P0135 Heated oxygen sensor heater circuit, bank 1' is now getting dangerous with the cold weather when the engine's cold, I wouldn't risk overtaking a milk float until the engine's hot.

I still haven't bought a workshop manual so I don't fully understand the fault. Your thoughts and possible fixing costs would be appreciated.

There's a second hand sensor on e-bay, incidentally, I was wondering if it's worth buying and getting my local garage to fit it.

Thanks again,

Nick

[ambermarine]

Folks,

Me again, with the industry-standard worn out LS400 Mk4. This oxygen sensor error, 'P0135 Heated oxygen sensor heater circuit, bank 1' is now getting dangerous with the cold weather when the engine's cold, I wouldn't risk overtaking a milk float until the engine's hot.

I still haven't bought a workshop manual so I don't fully understand the fault. Your thoughts and possible fixing costs would be appreciated.

There's a second hand sensor on e-bay, incidentally, I was wondering if it's worth buying and getting my local garage to fit it.

Thanks again,

Nick

Hi Nick

There are threads on the LexLs and the Lexusus sites on oxygen sensors and the replacement of ,depending on which one as failed, there are two to each side the main and the sub they are not too difficult to replace and there are heaps of suppliers in the states ranging from OEM to aftermarket.

The individual sensor can be checked with a volt meter either at the terminals on the sensor plug or on the engine terminal box but you need to follow complex instructions and have the info on readout voltages to determine what is faulty and what is normal.As the code for the Mark I is different to the code for the Mark 4 I can't determine which Sensor as gone on your car but someone on the forum will have a manual for a Mark 4 and should be able to give you that info.

[Mybikesacx500]

Folks,

Me again, with the industry-standard worn out LS400 Mk4. This oxygen sensor error, 'P0135 Heated oxygen sensor heater circuit, bank 1' is now getting dangerous with the cold weather when the engine's cold, I wouldn't risk overtaking a milk float until the engine's hot.

I still haven't bought a workshop manual so I don't fully understand the fault. Your thoughts and possible fixing costs would be appreciated.

There's a second hand sensor on e-bay, incidentally, I was wondering if it's worth buying and getting my local garage to fit it.

Thanks again,

Nick

The Sensors have a heater in them, as they don't work until hot, and the exhaust gas itself takes a while to heat the sensor to its working temp. A second hand sensor is quite likely to have a faulty heater, although it can be easily checked with a multi-meter and the info on which lead is which ( there are 4, 2 for the heater, 2 for the sensor itself, I believe the sensor voltage is about 1 volt, varying dependent on the oxygen level.

[toxo]

IMO they're all a royal pain in the arse to get to on a MKIV. The 2 nearer the engine are fairly inaccessible as they are in the part of the exhaust manifold nearest the dashboard, and the ones under the car are easy to reach but a bugger to get the wiring out as you have to remove carpet and heater ducts inside the car!

P0135 is a heater circuit fault with bank 1, sensor 1. Bank 1 is passenger side on a UK car and sensor 1 is the one nearest the engine i.e. in the exhaust manifold before the catalytic converter.

Have a read here, the MKIV LS400 and the LS430 are basically the same engine: http://us.lexusownersclub.com/forums/index.php?showtopic=55589

[TigerFish]

I can vouch for the bit in that write up about the VSC lights. Someone's code reader lit those up on my GS430 Sport, shorting the pins in the connector reset them but only after an initial major panic about a costly bill coming up. My own reader doesn't cause the VSC lights to trip.

[toxo]

IMO they're all a royal pain in the arse to get to on a MKIV. The 2 nearer the engine are fairly inaccessible as they are in the part of the exhaust manifold nearest the dashboard, and the ones under the car are easy to reach but a bugger to get the wiring out as you have to remove carpet and heater ducts inside the car!

P0135 is a heater circuit fault with bank 1, sensor 1. Bank 1 is passenger side on a UK car and sensor 1 is the one nearest the engine i.e. in the exhaust manifold before the catalytic converter.

Have a read here, the MKIV LS400 and the LS430 are basically the same engine: http://us.lexusownersclub.com/forums/index.php?showtopic=55589

Had a prod around on the spare engine I've got sat on a stand from a MKIV, and actually I reckon the one you've got that's broken is probably the easiest of the 4 to get to.