Where's O2 Sensor Bank 1 Sensor 1 for 1997 318is?

OBD scanner shows P0130 (O2 sensor Bank 1 Sensor 1) and P0135 (O2
heated circuit
for sensor Bank1 Sensor 1).
Autozone says 1997 318is has 4 sensors. 3 before catalytic converter,
and one behind.
Crawling under the car, I only see 2. One before and one after
catalytic converter.

Questions:
1. How many O2 sensors/monitors does '97 318is really have?
2. Where is Bank 1 Sensor 1?

Thanks in advance.

To my knowledge, it should have 2, one before and one after the CAT.




"liem00" > wrote in message
ups.com...
> OBD scanner shows P0130 (O2 sensor Bank 1 Sensor 1) and P0135 (O2
> heated circuit
> for sensor Bank1 Sensor 1).
> Autozone says 1997 318is has 4 sensors. 3 before catalytic converter,
> and one behind.
> Crawling under the car, I only see 2. One before and one after
> catalytic converter.
>
> Questions:
> 1. How many O2 sensors/monitors does '97 318is really have?
> 2. Where is Bank 1 Sensor 1?
>
> Thanks in advance.
>

Bank 1 Sensor 1 is upsteam of the catalyst.

Your car has 2 sensors, one upstream of the catalyst and one downstream
as you have observed and Jeff pointed out and as shwon below.

http://www.realoem.com/bmw/showparts...& hg=18&fg=10

liem00 wrote:
> OBD scanner shows P0130 (O2 sensor Bank 1 Sensor 1) and P0135 (O2
> heated circuit
> for sensor Bank1 Sensor 1).
> Autozone says 1997 318is has 4 sensors. 3 before catalytic converter,
> and one behind.
> Crawling under the car, I only see 2. One before and one after
> catalytic converter.
>
> Questions:
> 1. How many O2 sensors/monitors does '97 318is really have?
> 2. Where is Bank 1 Sensor 1?
>
> Thanks in advance.

Bank 1 Sensor 1 is upsteam of the catalyst.

Your car has 2 sensors, one upstream of the catalyst and one downstream
as you have observed and Jeff pointed out and as shown below.

http://www.realoem.com/bmw/showparts...& hg=18&fg=10

liem00 wrote:
> OBD scanner shows P0130 (O2 sensor Bank 1 Sensor 1) and P0135 (O2
> heated circuit
> for sensor Bank1 Sensor 1).
> Autozone says 1997 318is has 4 sensors. 3 before catalytic converter,
> and one behind.
> Crawling under the car, I only see 2. One before and one after
> catalytic converter.
>
> Questions:
> 1. How many O2 sensors/monitors does '97 318is really have?
> 2. Where is Bank 1 Sensor 1?
>
> Thanks in advance.

Thank you both for the valuable info.

Pashlipops wrote:
> Bank 1 Sensor 1 is upsteam of the catalyst.
>
> Your car has 2 sensors, one upstream of the catalyst and one downstream
> as you have observed and Jeff pointed out and as shown below.
>
> http://www.realoem.com/bmw/showparts...& hg=18&fg=10
>
> liem00 wrote:
> > OBD scanner shows P0130 (O2 sensor Bank 1 Sensor 1) and P0135 (O2
> > heated circuit
> > for sensor Bank1 Sensor 1).
> > Autozone says 1997 318is has 4 sensors. 3 before catalytic converter,
> > and one behind.
> > Crawling under the car, I only see 2. One before and one after
> > catalytic converter.
> >
> > Questions:
> > 1. How many O2 sensors/monitors does '97 318is really have?
> > 2. Where is Bank 1 Sensor 1?
> >
> > Thanks in advance.

A follow-up question.
I ended up buying two universal O2 sensors (#USOS-4000) to replace the
existing ones at this place;
see the last one on the list:
http://replacement.autopartswarehous...nsor&d p=true

The old sensors have 4 wires, 2 whites, 1 black, 1 grey.
New sensors have the same number of wires and colors.
I made wire-by-wire connection, but I still get engine faults: P0130 &
P0136.
Any idea?

Thanks,
Liem

liem00 wrote:
> Thank you both for the valuable info.
>
> Pashlipops wrote:
> > Bank 1 Sensor 1 is upsteam of the catalyst.
> >
> > Your car has 2 sensors, one upstream of the catalyst and one downstream
> > as you have observed and Jeff pointed out and as shown below.
> >
> > http://www.realoem.com/bmw/showparts...& hg=18&fg=10
> >
> > liem00 wrote:
> > > OBD scanner shows P0130 (O2 sensor Bank 1 Sensor 1) and P0135 (O2
> > > heated circuit
> > > for sensor Bank1 Sensor 1).
> > > Autozone says 1997 318is has 4 sensors. 3 before catalytic converter,
> > > and one behind.
> > > Crawling under the car, I only see 2. One before and one after
> > > catalytic converter.
> > >
> > > Questions:
> > > 1. How many O2 sensors/monitors does '97 318is really have?
> > > 2. Where is Bank 1 Sensor 1?
> > >
> > > Thanks in advance.