Bad O2 Sensor

[Boxster02]

Yesterday my CEL came on for the first time ;) I got code P1115. After research here I see it is a bad O2 sensor after the cat. conv. Do I need to change all the O2 sensors, or just the bad one? Also, how long can I go before I fix it? I was hoping a week would not hurt. One last thing, minutes before the CEL came on I had the GPS removed and some stereo wiring fixed, could that have anything to do with the CEL (wire not grounded, bad connection, etc..)? Thanks :drive:

[Loren]

P1115 Oxygen Sensor Heating Ahead of TWC, Bank 1 – Above Limit

Potential causes:

Heating current too high

– Heating resistance too low

– Short to B+

Heating current too low

– Short to ground

– Corrosion in connector

– Break in wiring except for a few litz wires

Open circuit

– Break in wiring

– Heating resistance too great

Internal resistance of oxygen sensor too high

– Open circuit in sensor line

– Oxygen sensor

[Boxster02]

Loren, thanks for the detailed response :D This morning I started the car and the CEL stayed on as expedted. I drove half a mile and to my luck the CEL turned off!!! :clapping: Started the car several more times today and it always turns off with the other warning lights (so I know the bulb is good). What could be going on?

[Loren]

Could be a bad connection or a bad O2 sensor heater (not uncommon).

How many miles on the car/O2 sensors?

[Boxster02]

Car is a tiptronic with 71K. Everything is original except the water pump. If the sensor heater is bad, shouldn't the CEL stay on?

[Loren]

O2 sensors can go bad after 60K. Like I said could be a bad connection or a bad sensor. To find out:

Check resistance of oxygen sensor heating.

1. Remove connector of oxygen sensor 1 ahead of TWC.

2. Connect ohmmeter to pin 1 and pin 2 of the oxygen sensor connector towards the oxygen sensor.

Display: < 2.6 Ω at 25 °C

Measure resistance between oxygen sensor housing and oxygen sensor heating.

1. Remove connector of oxygen sensor 1 ahead of TWC.

2. Connect ohmmeter to pin 1 of oxygen sensor housing and oxygen sensor connector towards the oxygen sensor.

Display: ∞=Ω

3. Connect ohmmeter to pin 2 of oxygen sensor housing and oxygen sensor connector towards the oxygen sensor.

Display: ∞=Ω