Verrry low long-term fule trim, bad fule economy and code P0170

[Robin Blakey]

Hey, Anyone have any ideas as to what might be happening?
-Long Term fule trim is -54%
-Fule consumption has doubled
-Stumbles half way up the rev range
-3 month old O2 sensor (pre Cat)
-New Cat
-MAP doesn't seem to be the issue. Its reading as normal (27kPa at idol and going up as I rev)
-Throwing code P0170

Any ideas would be great. Thanks!

Car is 2003.

 

[Robin Blakey]

Think I worked it out. I think the PCV system at the top of the rocker cover/intake is blocked up or something as there is a lot of oil getting into the intake. (Money shifted it HARD at a track day recently so that wouldn't have helped crack case pressure haha)
I think oil is getting burned, coating up the first lambda sensor, making it not be able to detect oxygen and thinking that the engine is running very lean. Then more fuel gets pumped in, not burning off and coating the lambda sensor in soot even more.

I cleaned the lambda sensor with contact cleaner put it back in and it immediately was better. Lambda sensor was reading richer before the cat than after, the Short term fuel trim went really high, 40 to 50% to try and bring up the long term.
Passed emissions in NCT (our MOT in Ireland)
Think I'll plumb in a catch can when I get the chance - at the moment I'm mopping up the oil in the intake and cleaning the lambda sensor every few weeks to get by