01 b4 down in power

M

marx

Sunday Drivers
Hi iv got a problem whit my b4 leggy she 2L twin turbo auto tiptronic my problem is when im crusing in 4th gear top gear at around 3000rpm when i slightly press the accelorater a check engine light comes on and when i take my foot off the pedal the light goes out she goes down in power a small bit when the light is on i pluged her in and the fault that came up was airflow metter iv changed it and light is still comming up has or does anyone know what is wrong oh and its totaly standerd no induction kit just an sti exhaust
 
Could be your knock sensor, did you connect the green and black plugs under the dash or just the black ones?
 
Try both together, I had something similar ages ago and it was the knock sensor that was gone, it didn't show up with both connectors plugged in on mine only the black ones, but sure give it a go with the both of them and see how you get on
 
I did the both of them engine light stayed on and all the different things started clicking and all that what should i be looking for when both are connected. I got a code off it whit just the black ones 22:knock sensor where is the sensor located i always figured that if it was the knock sensor it would go to limp mode all the time if it was faulty
 
The knock sensor is underneath the intercooler, can be a pain in the arse to do but should be no bother for any of the traders on here, even if the knock is gone the car will still run and drive normally, when mine went sometimes when I started her the check engine light would come on and it would take a dew mins to go off other times it'd be grand but just don't give it any welly until it's changed, they are about €140-150 from Subaru, hope this helps :thumbsup:
 
Would it also be the knock sensor if you are in low revs in 4th and but the boot down and as you are going int othe 2nd turbo it jerks and engine light comes on and you cannot go into the 2nd turbo? :ponder2:
 
what you getting when you connect the diagnostic connectors?
might be your vacuum pipes. best to connect the black connectors under the steering wheel and see what code u get
 
[quote author=Kielyb4 link=topic=23542.msg281243#msg281243 date=1273751402]
Would it also be the knock sensor if you are in low revs in 4th and but the boot down and as you are going int othe 2nd turbo it jerks and engine light comes on and you cannot go into the 2nd turbo? :ponder2:
[/quote]

Have you got a boost gauge fitted? That sounds a bit more like fuel cut to me. But i've not had to replace a knock sensor before so can't say if it is the same thing.
 
No there is no boost gauge. CDA were looking at it a while ago and cud'nt figure it out but they rang back and said its either vacuum pipe or knock sensor.

Like it rarely ever goes off, you just have to drive it a certain way and it happens.. :dontknow:
 
i pluged the black connectors and i got knock sensor num 22 i looked at all the vacuum hoses all are ok there not split cracked or not to soft
 
Disconnect the battery for 20mins-this will clear the fault code. Then go for a drive and see if the check light comes back-if it does connect the black plugs and read the code-if its 22 again its the knock sensor. 90euro from carroll and roche. replace it,clear code again and problem sorted
 
[quote author=Kielyb4 link=topic=23542.msg281281#msg281281 date=1273759302]
No there is no boost gauge. CDA were looking at it a while ago and cud'nt figure it out but they rang back and said its either vacuum pipe or knock sensor.

Like it rarely ever goes off, you just have to drive it a certain way and it happens.. :dontknow:
[/quote]

have u checked the vacuum pipes, i had an issue like this, and had to check them one was pissin air out of it. replaced and sorted.
 
Can somebody tell me where abouts in the engine bay I look? :dontknow:

Is it hte pipes on the tope of the manifold etc?

Cheers :smile:
 
Well i disconnected the batt. and took her for a test drive check engine came up again and i connected the black plugs and a different fault came up now 65: think thats the Differential Pressure Sensor where is that located could anyone tell me
 
Thanks alot that was realy helpful strange that the faults totaly change il get that sensor hopfully that will sort it :pray:
 
[quote author=Kielyb4 link=topic=23542.msg281879#msg281879 date=1274023687]
Cheers hego :thumbsup:
[/quote]
no worries man, hope it helps you. got my boost sorted again after many issues :comp26:
 
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