need help asap vp 5ltr

[slepar]

ok my car has been running crap lately i done the fault code check and its coming up with:

44, oxygen sensor (lean)
15, coolant temp sensor (voltage to high)


first question is is there only one o2 sensor on a vp 5ltr? it has extractors and a cat back exhaust nothing custom

and were is the coolant temp sensor?

need this info asap so all help much appreciated

cheers ricky

[50LTRv8]

I am assuming your VP will be the same as my VT 5 Litre.

There will be 2 of them, both right near the cat, they just undo with a open ended ring spanner.

The catch is replacing the one on the drivers side, the plug for it is up on top of the gearbox which I could not get my hand into, the other one can be done in 5 min. Also make sure the ones you purchase come with some anti seize on the threads or you will have to buy some from repco or supercrap. Just make sure you don't put it on the sensor bit and you will be fine.

The other thing to look out for is see how many wires are on your sensors, there are 2 versions, 2 wire and 4 wire.On ebay it specifies how many wires on each sensor loom, simply get the one that you already have.

I am not sure on the coolent temp sender though but someone else will

Good luck

[Not_An_Abba_Fan]

There is only 1 O2 sensor on the VP.

The coolant temp sensor is under the throttle body.

[Cheap6]

Yes, only one O2 sensor on VP V8.

The coolant sensor fault could cause the O2 sensor fault so figure that out first.

First step in diagnosis, after extracting the codes, is to clear them (remove the EFI relay > 10 seconds) and confirm that they have been cleared. Then get the code or codes to re occur, = Check Engine Light in the dash on, even briefly, and note the circumstances.

High coolant temp voltage = open circuit somewhere between the sensor and the ECM so check the wiring connector at the sensor => 'wiggle' test, which is just what it sounds like; look for the CEL when the wires/connector to the sensor are moved with the ignition on.

One guess would be a faulty ECM; the ECM switches in and out a short around one of two resistances in series inside the ECM (which are also in series with the temp. sensor). It's pretty common for the printed circuit board to develop a crack and the second resistor to be absent when the ECM thinks it is present or vice versa.

The switching should occur with a coolant temp of around 50C i.e. with a voltmeter between terminal C10 - the terminal numbers are moulded into the connector - at the ECM and earth you should see a step change in the voltage frome ~1V? to ~3or 4V after 2-3 mins of running from cold.

Sometimes the ECM will trigger the fault code when subject to mild jolting eg. watch for the CEL and voltage change while tapping the ECM case with your fingertips.

[50LTRv8]

There is only 1 O2 sensor on the VP.

The coolant temp sensor is under the throttle body.

Thanks for the info

[PaRaDoX]

I am assuming your VP will be the same as my VT 5 Litre.

There is only 1 O2 sensor on the VP.

this is why you don't assume :P

is it a 1 wire or 2 wire? if its a 1 wire its grounded via the headers and your extractors are probably not doing a good job of grounding.

[pow3rslave]

does the v8 suffer the v6 issue with extractors causing o2 sensor errors?

[greenfoam]

No, not at all (thankfully), they get plenty hot enough on the 5 litre