04 Sti PPP Overboost
 

I have an 04 Sti with PPP, done 41k.

I had an CEL come on, which was identified as a front lambda sensor. I replaced this with a second hand one from RCM.

All seemed fine, but now I sometimes get boost up to 2.0 followed by the CEL coming back on. It drives fine with this on and it goes off again after about 2-3 journeys.

I havent got is scanned again, but will later today hopefully.

So:

1) What boost should you get on this car (seems to be about 1.4 usually)

2) Does it sound like a faulty lambda and should I not be such a cheapskate and get a new one?

Thanks for any help.

Any help????