Error code question

[62Sunbeam]

So I've replaced the fuel temp sensor, the coolant temp sensor, the spark plug wires and the O2 sensors in an effort to get rid of my hot start problem and while it's been relatively cool here the Disco still sometimes starts a little roughly when the engine is hot and it's hot outside.
Here's my question: I was driving yesterday at a nice even pace ( engine running smoothly, no problems) and when I got into town the check engine light came on and I got a 45 code.

Why? There was no noticeable mis or rough running and the sensors are new. I know that when I get on the throttle there's not much in the way of acceleration. Plugs look OK.

Any help?

Thanks again all.

Eric
'95 Disco 167K miles

 

[joey]

Here is what I have found:

Code 44 - Lambda sensor A - left bank
Code 45 - Lambda sensor B - right bank

If one of these fault codes is displayed check the wiring to that particular lambda sensor.

If both codes are displayed, the voltage supply to the heater coils of the sensors must be checked. Refer to test 26, continuity test procedure.

 

[62Sunbeam]

I know it's the right bank O2 sensor. I've already checked the connections and they seam fine.
I don't believe the 95 Discos had O2 sensors with heater elements although I could be wrong.
What is the test 26 continuity test proceedure?

Thanks

Eric
'95 Disco 167K miles

 

[joey]

Here is everything I have found so far:

Heated oxygen sensor (HO2S)
The oxygen sensors consist of a titanium metal sensor surrounded by a gas permeable ceramic coating. Oxygen in the exhaust gas diffuses through the ceramic coating on the sensor, and reacts with the titanium wire altering the resistance of the wire. From this resistance change the ECM calculates the
amount of oxygen in the exhaust gas. The injected fuel quantity is then adjusted to achieve the correct air/fuel ratio, thus reducing the emissions of carbon monoxide (CO), hydrocarbons (HC),and oxides of nitrogen (NO 2 ). Two HO2 sensors are fitted, one in each exhaust downpipe just ahead of the catalyst.

Note that if the wiring to these sensors is crossed, the vehicle will start and idle correctly until the sensors reach operating temperature. Then the ECM will read the signals from them and send one bank of cylinders very rich and the other very weak. The engine will misfire, have a rough idle and emit black smoke, with possible catalyst damage. In the event of sensor failure, the system will default to ’open loop’. Operation and fuelling will be calculated
using signals from the remaining ECM inputs. The fault is indicated by illumination of the malfunction indicator light (MIL). ECM diagnostics also uses HO2 sensors to detect catalyst damage, misfire and fuel system faults. North American vehicles have two extra HO2 sensors mounted one after each catalyst. These are used to determine whether the catalysts are operating
efficently.

CAUTION: Although robust within the vehicle environment, HO2 sensors are
easily damaged by dropping, excessive heat and contamination. Care must be exercised when working on the exhaust system not to damage the sensor housing or tip.

 

[62Sunbeam]

Is there a wrong way to plug in the O2 sensors? They were dirct replacement Wagner sensors and the had the same plugs as the previous sensors and they plugged right in and there seemed only one way to do so.

There was no sign of the simptoms of which you write. It just starts rough when hot and like I said originally the 45 code cam one after driving for about a half hour having gone from driving along at a nice clip to stop and go city traffic.

Thanks for your help.

Eric

 

[62Sunbeam]

Could a leaky exhaust gasket before the catalyst be causing the problem????

'cause I have one.


Eric