O2 sensor codes and parts needed

Hi,

If anyone can provide me insight I would greatly appeciate it. My service engine light came on, mechanic checked codes and came back with two bad oxygen sensor codes one for front and one for rear (P1185, P1193).

My question is that given that there are four 02 sensors, do the codes indicate which ones are bad or do all four have to be replaced (truck has 111,000 miles and for the six years I have owned it I haven't changed any of them).

If anyone has any idea as to which ones need to be replaced and the parts numbers I would greately appreciate it as I just failed my emmissions test and need to fix the problem quickly.

Thanks,

Mark

Just in case someone else needs this info in the future here is the information provided by Les Parker from Rovers North.....

Mark,
Ref the "P" codes, they pertain to individual sensors, thus :-

P1185
Oxygen Sensor Heater Circuit Open Upstream
P1186
Oxygen Sensor Heater Circuit Short Upstream
P1187
Oxygen Sensor Heater Circuit Short Upstream
P1188
Oxygen Sensor Heater High Resistance Upstream
P1189
Oxygen Sensor Heater Type 1 Low Resistance Upstream
P1190
Oxygen Sensor Heater Type 2 Low Resistance Upstream
P1191
Oxygen Sensor Heater Circuit Open Downstream
P1192
Oxygen Sensor Heater Circuit Short Downstream
P1193
Oxygen Sensor Heater Circuit Open Downstream
P1194
Oxygen Sensor Heater High Resistance Downstream
P1195
Oxygen Sensor Heater Type 1 Low Resistance Downstream
P1196
Oxygen Sensor Heater Type 2 Low Resistance Downstream

I hope this helps.
We have had great sucess with the ProLine sensors, as yours is a 99 Series I, the sensor you need is PLD292 priced at $135.98 each.
We have good stock on this.
If they have not been replaced for over 70k miles, I would seriously consider replacing all 4 at the same time. On Series I Discovery, all 4 are the same.
Please advise,

Les

Quote:

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Originally Posted by alligatorfoot

Hi,

If anyone can provide me insight I would greatly appeciate it. My service engine light came on, mechanic checked codes and came back with two bad oxygen sensor codes one for front and one for rear (P1185, P1193).

My question is that given that there are four 02 sensors, do the codes indicate which ones are bad or do all four have to be replaced (truck has 111,000 miles and for the six years I have owned it I haven't changed any of them).

If anyone has any idea as to which ones need to be replaced and the parts numbers I would greately appreciate it as I just failed my emmissions test and need to fix the problem quickly.

Thanks,

Mark

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I'd be surprised if all 4 went unless something else is seriously wrong. On OBDII cars the front 2 sensors are for managing the engine mixture when running "closed loop" the rear 2 or to test and see if your cats are still working. I'd start with the fronts and go from there.

There are many places to buy o2 sensors. Atlantic british, rovers north, etc. expect 100-150 dollars each for oem style ones that are plug and play. If you want to crimp wires you can find some cheaper.

I actually ended up changing all 4.

I really did not notice a difference in engine performance however my gas mile dramatically improved. The main reason for having the work done is that I failed the state emmissions test by a factor of 2. After the installation of the 02 sensors my numbers were literally non existant (1ppm vs 220ppm as the passing standard). I also used aftermarket o2 sensors and my mechanic felt that the quality was on par w/ oem.