engine problem

[mph2401]

hi everyone...im new here and i was wondering if anyone can help. i have a 1995 colour concept golf gti 2.0l 8v.it has a scorpion back box fitted and a pipercross induction kit.the problem is that three days ago it started idling very badly.i also noticed that it loses power at 5000rpm,almost like a limiter. i had a guy put it on a fault code reader and it threw back 2 faults..1 crankshaft position sensor not working correctly and 2. air reading is out of range,something to do with the lambda sensor. i notice when driving from cold there doesnt seem to be problem but when the car heats up it runs badly. ive changed the distributor cap and rotor arm but to no avail.can anyone help? i also have found that if i leave the car sitting switched off for 15 minutes or so and drive it again i can get the full revs back and the car is ok....help!!!

[...joe]

sorry i'm not going to be too much help here..... but surely if your car showed a problem with a crank sensor and a lambda probe problem, changing the distributor cap and rotor arm aren't going to solve either problem?? the lambda probe measures the air fuel mixture coming out of the exhaust at the bottom of the down pipe so i'd get that checked out first. i'm not too sure about the crankshaft postion sensor though? sorry!

[mph2401]

ive just browsed through all the other posts and from what i can see it could either be the sensor or the maf sensor...has anyone any ideas on how to get at the crankshaft/hall sensor. the haynes manual doesnt even mention it...