had the dreaded check engine light come on on sun nite, read the fault codes and it came up with 23 (mass air flow sens) 32 (O2 sens) and 22 (knock sens) in that order is this going to be a def change all sensors cause im thinking that could be quite expensive glad for any help in advance

 

Bit more history needed, were all the codes cleared before so these are definatley all just set?

Did you only get one MIL/CEl event, so they are related

If the answer to both is yes, its sounds more like a loom problem on a common wire (sensor ground or 5V feed) , not a sensor problem at all!

Simon

 

What car is it, Hows the car acting/driving??
Could try a ECU reset, iirc the ECU stores codes so is poss you could be reading old faults

JollyGreenMonster.co.uk

hth

 

nah ive had the check engine light apper quickly a couple of times in the past but seen as i dont drive it that often only just got round to reading the codes i know it absolutly stinks of fuel sometimes (guessing lamda making it over fuel)

 

its on a k plate classic wrx turbo cheers

 

it did have a really dodgy halfords induction kit on it wich ive changed for and apexi one now hoping the maf sens code is an old one lol

 

Get them cleared so you know what is 'current', otherwise your wasting your time! If its that rich the O2 sensor would be my No1 suspect.

Simon

 

Mmmmmmmm, same as mine, you can check the O2 sensor, put a volt meter on it it should read between 0.1(very lean) and 0.9v (very rich) it will bounce all over on idle but should be steady and toward 0.9v on boost.
Pic below shows O2 sensor wire on ECU, hth

 

cheers for all the help guys will clear them this weekend and see what comes back up

 

A dodgy maf will set all these codes off! maf knackerd will cause the car fueling to **** up which the lambda sensor will pick up and the fueling problem will cause the engine to det and the knock sensor will pick it up

 

As above.

Faulty MAF will knacker an O2 sensor causing overfuelling and knock activity.

Reset ECU and see what codes come up. If they all come up again, change MAF and reset again, chances are though, the O2 sensor will be shot.

After you change the MAF, if the car drives badly and is hesitant, unplug the O2 sensor and try that. It should revert to default settings if unplugged.

 

well o2 sens changed light stayed off for a bit then hey presto back on it comes im going with maf sens def now and they ent cheap are they

 

I've got one here mate, Send me a pm and make me an offer

 

right all ive changed the lambda sens and the maf sens tried clearing the fault codes and i cant do it to save my life lol whats the secret? i plugg the green connectors togeather and the black ones and then drive it but the CEL just keeps flashing the fault codes at me

 

Scoobypedia | Trusted knowledge for everything Subaru | Knowledge / ECU Reset

 

right cleared the fault codes i had and the only one coming back is 22 (knock sens) so hopefully replacing this will cure my troubled scoob?????????