I have recently purchased a P1 a few weeks back and this is my first posting! ;-)

I have recently fitted a downpipe / centre section / rear box - Scooby sport to my P1. I have now noticed an decrease in power/surge since being fitted.

I suspect the lambda sensor, as the Lumenition air/fuel meter is not working (which was working on another car - but never on this car since being fitted). I am currently getting 220 miles to the tank full.

Also if i rev the car hard (after being warmed up! ;-)) on the drive the waste gate doesnt move a mm! I know when they fitted the exhaust that they twisted and man handle the waste gate and would like to know if and when it should move (if at all when standing still and revved?)

Any help would be much appreciated.

How can i test the lambda and the waste gate?

 

Nothing really should happen at all when the car's standing still - there's no load so nothing for anything to do!
The best way to test the lambda sensor is having a working AFR meter oddly suddenly stop working, I suspect .
Lambda is used in closed-loop (cruising), not acceleration, so affects your mpg if not working. You should also have an error code coming up on the ECU - although if this works anything like the MAF's 'error code', it only tells you something's wrong when the car is barely functioning.
I recon the lambda has gone, like you say, but it's worthwhile listening to someone who knows what they are talking about instead

 

Thanx Nom for the reply,

So am i right in thinking that if that lambda sensor has gone, it will ONLY affect mpg and NOT performance?

And any help info on how the waste gate works? and to test it?

Cheers,

Mark

 

The wastegate you'd know about as either boost is lower or higher (either one by a lot) than usual - it either won't be openening properly (boost will overshoot & you'll likely get fuel cut which you'd know about) or it's always open in which case you're unlikely to get boost much at all.
At least, that's the vague affects - could be stages in between. Best 'test' is measure the boost via a boost guage.
On the lambda - you don't want to be using that one if it's not working! AFAIK, P1s run leaner than the normal UKs anyway, so you want to make sure it's running right. On top of a properly calibrated AFR meter, you should probably have something to detect knock - I'd recommend the KnockLink (with its own sensor) & also the LambdaLink if your current AFR seems iffy - I believe that the LambdaLink should be more accurate than others as it can be calibrated (some sources such as BR Developments I believe actuall calibrate it for you).
Hope something in there helps!

 

The lambda sensor is only used by the ecu off boost and up to about 4500 rpm, the only effect that will have if it plays up is poor fuel cunsumption and rich/choking running in cruise mode.

What you have done is lean out the mixture by fitting the mods, if your fuel pump is the weaker type then that could be the case causing it to behave differently. Orm you could have a dodgy maf which would then cause the same thing.

Te wastegate won't move untill you make boost of a certain level.

You need to get it checked out pdq as there is something amiss from what you've said. Assume you still have std induction ?

Bob

 

Thanks for the info...

I am having the car checked at a main subaru dealer(friday), but worried that they will make me pay for the lambda sensor (if faulty)when they see the scooby sport system and that i have spliced into the wiring loom for the feed to the afr meter? , although i have spliced into the loom NOT the lambda sensor!)
In any ones experience, do you think they will not warranty it now, because of the change?

Also if they test the maf and its faulty will they replace it under warranty? as the standard air box is still attached.

However i am thinking of replacing it with a blitz induction kit and a forge dump valve. I think i will wait til the garage has checked it all first tho!

Where do i get a knocklink sensor from and how much and are they easy to fit (diy?)

Thank you, Mark ;-)

 

I have now found out that there are TWO types of lambda sensors.
0 to 1 volt and 0 to 5 volt (and 2 wired non heated and 3 / 4 heated)

Thelumenition afr meter i have is a 0 to 1 volt meter.

Does any one know whether the Subaru is a 0 to 5 volt lambda?
If it is then this is why my afr is not working correctly.

Can any one let me know where to order a afr meter (0 to 5volt?) and knocklink sensor from? and is the knocklink sensor easy to fit?

Cheers,
Mark

 

sorry, I'm pretty sure it's 0-1 volt

 

BR Developments, amongst others, do the KnockLink. Their address is presumably in Bob's profile up there where he replied
I wouldn't go near a Blitz air filter if I were you - they seem to go hand & hand with destroying MAFs, which you want to be pretty careful with!
Subaru dealer may well not be a lot of help. They usually aren't. They also don't have the kit to test to see if there's a problem...

 

The lambda sensor is a normal narrow band type which generates 0-1 volt, the lambda sensor is considered a consumable, Bosch suggest replacement every 30,000 miles as a matter of course, its not unknown for them to play up after as little as 15000 miles.

Which wire did you splice into for the afr meter ? It should be the one whch ends in the gold terminal in the connector.

Bob

 

A good way to check the sensor is to remove it from the downpipe, hold in a vice, connect a digital voltmeter positive to the signal (gold terminal) and negative to the ground terminal. Use a small blow torch and heat the nose of the sensor whilst observing the voltmeter, you should see it quickly rise to 0.9v (ish), when you remove the flame it should drop close to zero almost immediately.

 

Thanks for the info bob etc,

Yes i have spliced into the wire with the gold connector.
I will order a replacement lambda sensor to be on the safe side.
Where is the best/cheapest place to order one from?

btw, i have ordered your knocklink sensor and display!;-) preventions better than a cure!

If my engine is running lean because of the exchaust system, what is the solution?

Cheers... ;-)