O2 sensor again

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turbazz

Member
Previously I was not getting a reading so I decided to take it out...


Right so managed to get it out gave it a clean. Notice the wire was broken too! The red one. Soldered it up put it back together.


and now am getting a reading (using a Nissan software called tecu)


Now I'm driving my car it feels worser there is no top end power after 5500rpm!


Sensor voltage is hard to read as there is a delay. It goes up and down though..


What voltage reading should I get at idle?


My doubts are..
. Not tightened the sensor hard enough,
the washer needs replacing,
need to set my boost controller again(i'm not getting more than 0.9 used to get 1.1)
Sensor is fcuked
 
PobodY

PobodY

Moderators
Staff member
The voltage isn't what the ECU is reading; it's the change in resistance of the sensor. - It's a titania rather than zirconia probe, so it's not like the majority of sensors.

I'd go with the probe is knackered. - Maybe soldering the wires has changed the resistance, and now it's got an offset? Try disconnecting it and see if the car runs better (it doesn't need the lambda sensor, but your fuel economy will probably suffer).

How did you clean it? Is it possible that's damaged the surface of the probe?
 
T

turbazz

Member
I used brake Cleaner. I don't understand is it's affecting me after 5500rpm.. Wah is The part number for the sensor
 
PobodY

PobodY

Moderators
Staff member
BMCC said:
I would have thought the o2 sensor is only used in closed loop conditions.
Click to expand...
It is; that effectively means just when you're cruising at partial throttle.

I wasn't thinking about that bit... just that a titania sensor doesn't work like a zirconia one. :oops:

Looked at the TPS?
Base timing?
ECU temperature sensor (rather than the gauges)?
Boost leak?
 
B

BMCC

Member
PobodY said:
It is; that effectively means just when you're cruising at partial throttle.

I wasn't thinking about that bit... just tit at a titania sensor doesn't work like a zirconia one. :oops:

Looked at the TPS?
Base timing?
ECU temperature sensor (rather than the gauges)?
Boost leak?
Click to expand...
Yes I was thinking that at 5500rpm and full boost you'd be on full throttle so the o2 being knackered shouldn't be causing a lack of power. Ecu engine temp sensor being knackered could cause the ecu to fuel incorrectly so worth changing this as the sensors inexpensive. Any popping from the exhaust?
 
T

turbazz

Member
It is really funny. I want to get to the bottom of it. Car was working fine (sensor was dead on consult) before I soldered it.

after the soldering sensor was showing readings. But the car was not driving right I did not touch anything Else.

Sorry which is the engine temperature sensor? How do I check this
 
PobodY

PobodY

Moderators
Staff member
Nope, that's essentially a temperature probe that makes a light come on to tell you the catalyst is really hot and liable to set something on fire.
 
B

BMCC

Member
Unplug the 02 and see if it feels more like it used to. If it doesn't then i would have thought that the 02 sensor is ruled out and your problems lie else where.

The engine temp sensor is on an elbow at the back of the engine. Look down a little in front of the master brake cylinder and look for a red ended sensor down by the inlet manifold. I've removed this and tested it and it was ok (according to the manual) but changed it anyway and the car ran better (no popping from the exhaust). So maybe it is something you can't really diagnose with a multi meter.
 
B

BMCC

Member
If it is reading low the ecu will be over fueling as it thinks the car is not properly up to temp.
 
PobodY

PobodY

Moderators
Staff member
turbazz said:
This would come up on the fault check as engine temperature sensor?
Click to expand...
In theory, but it's not a diagnostic part so if it's giving a reading the ECU may not register a fault. I think it only registers a fault when there's no signal, but I could be wrong about that.

The give-away could be that the diagnostic software is saying the coolant temperature is 20ºC, but the gauges say more like 80ºC (I've just made those temperatures up).
 
B

BMCC

Member
No check light for ECT if you pull the plug or the ecu isn't getting a reading on it the fans will come on.
 
B

BMCC

Member
if you pull the plug from the sensor it will not cause the engine check light to come on, instead the radiator fans will come on. Unplug the sensor and you will see what I mean. By unplug I don't mean remove the sensor, just pull the plug from the top of the sensor
 
T

turbazz

Member
Shall I check if my coolant temperature is the same as the gauge on the dashboard?

sorry is coolant and engine temperature different things
 
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