engine management problem

**vectragsi3.2** · 22nd June 2007, 20:52

hi hope someone can help i have a car with a spanner going through the middle when i put the ignition on but when i switch the engine on it dissapears! had a tech 2 done and it come up with the fault of o2 sensor bank 1 but they dont know what the problem is! i also noticed that my petrol is going rather quickly aswell.

**Gsi3.2** · 22nd June 2007, 20:58

it says that you have had a lambda sensor fault within the last 25 restarts..after 25 restarts the light will not reappear when you put the key in.lambda failure will make the car run a bit richer, so thats to be expected, but you never bought the GSi for it's economy did you..

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if they don't know what the code means, then you need to find a better garage

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**vectragsi3.2** · 22nd June 2007, 21:04

does that mean i do not have to replace any parts? also i have had the fault reset 3 times this week but comes back as soon as i stop switch the engine off then put the ignition on!!

**Gsi3.2** · 22nd June 2007, 21:08

if you disconnect the battery on the car for about 20 mins, then reconnect and restart the car, and the fault light does not appear then no you don't. It will just mean that the lambda sensor went out of the expected range of readings it was giving..and that is enough to cause a fault light to appear..

**vectragsi3.2** · 22nd June 2007, 21:11

could it be the air flow meter? also vauxhall mentioned it could be the cat?

**Gsi3.2** · 22nd June 2007, 21:19

it won't be the AFM as that hasn't flagged a code..and it's VERY unlikely that it will be the cat causing the problem as the lambda sensor is pre cat and so unaffected by it's operation..the code says lambda sensor, so if it faults again, then swap it out..but until then i'd just reset the ecu by removing the battery lead and see if it reappears

**vectragsi3.2** · 22nd June 2007, 21:24

cheers will try that how will i know which sensor it could be as there are two on each bank?

**vectragsi3.2** · 23rd June 2007, 17:51

hi i did the reset the fault light came back on within an hour!! it now smells of petrol!

**Sundance** · 23rd June 2007, 21:29

Originally Posted by vectragsi3.2

hi i did the reset the fault light came back on within an hour!! it now smells of petrol!

It could very well be the airflow meter, if the afm isnt reading correct then it may not be getting the correct amount of fuel, very common with a fault code of p0170. just because there isnt a code for the afm doesnt mean it isnt faulty!! you very rarely get a code for the afm, and if you do its normally something else causing the fault!! Diagnostic codes dont always make things simple for us