I have a 01 Lexus IS300 , my OBDII reader show these three code
P0135 ,P0141 and P0155 , and they happen to be O2 Heater , so I went
ahead and changed out the o2 sensor, I purchased a Bosch universal
sensor 4 wires. ( well, I bought them online and they happen to be 4
wires o2 sensor for ford , but then I assume all 4 wires sensor are
the same ...and I realize that the heater resistance are different
between car , correct me if I"m wrong) as a result the code still pop
up , so then I tried to trick the computer by use the working sensor
which is the B2S2 ( no code appear to be for the sensor) so I shared
that Heater signal to all other sensor, drove for 120miles no code and
the CHK engine light come back on again, now it pop a code for
P0161 .... I'm so confused and tired of this engine light... can
somebody help me


I haven't measure the Universal (ford) Bosch O2 Sensor heater
resistance but I have been reading up they are about 4-8ohm.... the
FSM said it should be at 11-16ohm , can I trick the ECU by adding a
resistor to it ? or I really have to get the Denso O2 sensor?

are all the Denso sensor heater resistance from 11-16ohm?

<h2ocarlos@gmail.com> wrote in message
news:1194931607.481871.214470@v2g2000hsf.googlegro ups.com...
>I have a 01 Lexus IS300 , my OBDII reader show these three code
> P0135 ,P0141 and P0155 , and they happen to be O2 Heater , so I went
> ahead and changed out the o2 sensor, I purchased a Bosch universal
> sensor 4 wires. ( well, I bought them online and they happen to be 4
> wires o2 sensor for ford , but then I assume all 4 wires sensor are
> the same ...and I realize that the heater resistance are different
> between car , correct me if I"m wrong) as a result the code still pop
> up , so then I tried to trick the computer by use the working sensor
> which is the B2S2 ( no code appear to be for the sensor) so I shared
> that Heater signal to all other sensor, drove for 120miles no code and
> the CHK engine light come back on again, now it pop a code for
> P0161 .... I'm so confused and tired of this engine light... can
> somebody help me
>
>
> I haven't measure the Universal (ford) Bosch O2 Sensor heater
> resistance but I have been reading up they are about 4-8ohm.... the
> FSM said it should be at 11-16ohm , can I trick the ECU by adding a
> resistor to it ? or I really have to get the Denso O2 sensor?
>
> are all the Denso sensor heater resistance from 11-16ohm?
>

You didn't mention the mileage on your car, but the sensors may be covered
by the emissions warranty.

If the resistance through the "universal" O2 sensors are not the same as
specified in the FSM, then they are probably going to give you a trouble
code. Adding a resistor to the circuit is probably not a good idea because
the sensor heaters will not warm up properly. While not all aftermarket
sensors are bad, I have seen more problems related to using aftermarket
sensors than OEM sensors.

It seems odd that all 4 sensors would give trouble codes so close together.
By any chance, do you use really cheap gas or make lots of short trips?

Before you go and buy more O2 sensors, check the voltages for the O2 heater
circuits to make sure the wiring related to those circuits are not damaged.
--

Ray O
(correct punctuation to reply)

<h2ocarlos@gmail.com> wrote in message
news:1194931607.481871.214470@v2g2000hsf.googlegro ups.com...
>I have a 01 Lexus IS300 , my OBDII reader show these three code
> P0135 ,P0141 and P0155 , and they happen to be O2 Heater , so I went
> ahead and changed out the o2 sensor, I purchased a Bosch universal
> sensor 4 wires.

Huge mistake. Get the right sensors. I'd get a Denso, or Toyota OE.
You have four sensors, all the four wire type, two before the
converter and two after. The OE applications have different part
numbers for all four sensors. I assume this is due to variations in
the connectors. Splicing wires from your new universal sensors to the
old connectors is a good way to cause problems on low power circuits.
Do the right thing, get the right parts. They may cost more, but they
will work right.

You should also check your emissions warranty, sensors may have a
longer coverage period that other components - especially if you are
in California.

Ed