Yes, you can use an aftermarket sensor. I use Bosch sensors.

The Heater Circuit is a heating element that is internal to the sensor. The
sensor will ultimately get hot because of the heated exhaust gasses that are
passing by, but while it is cold, the readings are not reliable and the
computer can't make the proper adjustments to fuel metering. The heater
inside the sensor will allow it to come to operating temp very quickly.

Bank 1 Sensor 2 is the sensor that is behind the CAT. It is easy to replace,
and requires a tool that resembles a spark plug socket. The after-CAT sensor
_may_ be able to be removed with a standard open end wrench, but if not, the
socke that resembles a spark plug wrench is easy to find and reasonably
cheap to buy.

There is a very good chance that the guys that replaced the exhaust manifold
had no idea that the sensor wasn't working. In fact, there is a very good
chance that it failed subsequent to the service they did.





<shettync@gmail.com> wrote in message
news:1171675627.674026.220460@l53g2000cwa.googlegr oups.com...
> My 96 corolla DX 1.8L 4cyl, flunked the emission test (state of ct)
> with the following
> reason code:
> P0141:O2 Sensor Heater Circuit Bank 1 Sensor 2
>
> I recently spent $400+ and replaced the exhaust manifold &
> gaskets(dealer parts) at a local Meineke. They never mentioned about a
> broken o2 sensor. I called the dealer and found out that these o2
> sensors go for $160.
> The shady local emission place guy didnt mention about how much he
> would charge to get this fixed. Can I use a after mkt item? I have 30
> days to reappear for a retest.
> Is this something which I can fix or do I need to pay a visit to the
> shop?
> Any suggestions?
>
> ~~N
>