After reading the flash code from my ECU, it stated code 34, which is Det sensor, i then tested the O2 sensors using the ECU, the right one was fine, but the left one was reading lean (with ocasional blips to rich if the revs were blipped). my logic tells me that, if the left o2 sensor is saying lean (due to it being f**ked) then the ECU would put more fuel into the left bank, (hence my majorly over fueling) which would then possibly cause pre ignition (detenation) which would then come up with fault code 34.

 

Does this sound possible?

 

has anyone have any sources for any o2 sensors, its a manual twin turbo import. my local nissan place told me £117 + VAT, and they're apparently on 3 weeks back order.

 

chears

 

Steve

unlikely the 2 are related - code 34 means the det sensor circuit is faulty, not that it is actually detecting det.

 

You could try MJP (mike) a trader on here for sensors :)

Unlikely, o2 sensors tend to make the car run rich when they fail/start to fail. A buggered O2 sensor is likely to put the car into base map...ie higher fueling. Det picks up knock which is generally caused by pre-ignition as you've suggested.

so if i changed the o2 sensor, would that put the mapping right, or would it then need to get proffesionally remapped?

 

so basically i'm looking at a new det sensor, and a new o2 sensor?

No, base map is safety mode. You wouldn't need to do anything. Resetting the ECU would mean it would 'learn' again. Simply unhook the battery for a few minutes.

 

Code 34 will tend to throw up if the car is in safety mode anyway. If your ECU is reading a buggered O2 sensor, then the ECU will put itself into safety mode and you'll get Code 34

 

I'd replace the O2 sensor if you know it's faulty, reset the ECU (disconnecting the battery) and run it for a few minutes, then check for codes.

nice, so code 34 doesn't necessarily mean a faulty det sensor? I only know that the o2 sensor is buggered from doing the checks on the ecu, it was flashing the required amount in the 10 seconds on the right sensor, but not on the left, as i said it more often said it was running lean, was a bit strange really. but it is now terribly over fueling. I'll have to source a new one.

 

thanks

No,no,no... Code34 = No signal received from the Det sensor.

 

The only cause of a code34 is either Faulty det sensor, or a problem with the wiring/connectors between det sensor and the ECU.

 

It will put the car in Safety mode, but safety mode or Detonation does not cause a code34.

Edited July 15, 201015 yr by Yowser

For the o2 sensors...the ECU runs a closed loop system. This means that at idle the o2 sensors are not being read by the ECU.

 

To test the o2 sensors you need to hold the revs at 2000rpm+ , and both o2 sensors should be continously swinging from lean to rich.

 

..and you need to do it with the engine fully warmed up.

For the o2 sensors...the ECU runs a closed loop system. This means that at idle the o2 sensors are not being read by the ECU.

 

To test the o2 sensors you need to hold the revs at 2000rpm+ , and both o2 sensors should be continously swinging from lean to rich.

 

..and you need to do it with the engine fully warmed up.

 

That was the test i did for the o2 sensor, as i said the right one was ok, just the left seemed a bit ill.

 

gunna reset my ecu tomorow night, then take her for a spin and check her again, either way i'm gunna need new o2 sensor by the sounds of it, as for the det sensor, it may just have to be a dodgy short for the time being.

Quite often its the connector or the det sensor loom, rather than the det sensor itself. Its quite common to bypass the Sensor with a 1mohm resistor as a quick fix.

 

Unless the car has overheated badly in the past, they do tend to melt when that happens.