I completed some work on the mini including a full new maniflow injection manifold + RC40 exhaust (keeping the CAT), new coil, leads, plugs, distributor cap + rotor arm and then the car was setup (motion gap and stepper motor) according to MEMSFCR instructions etc.
The car was then running well (as far as I could tell). I reset the ECZ values as the long term fuel trim was -30% and i beleived this was down to the car running rich (I know it was as the plugs were black and the lambda sensor circuit was defect.)
I then went off to an EPIC IMM2023 in Tuscany Italy with some unbelievable roads and an awesome 3 days of some HARD driving😁😁😁😁.
Got home and decided to check everything out and these are my findings -
long term fuel trim was back at -28%
Stepper motor 33 (at temperature)
MAF 30 - 33 at idle
motion gap still ok
Due to the very low Long term fuel trim i checked the plugs and they looked good with no. 2 & 3 slightly blacker than the other outer two.
now because The lambda sensor with the maniflow is reading the exhaust from the outer two exhaust ports only could this be the reason why my long term fuel trim is so low???
Should i be worried with this low trim our should I concentrate on the short term fule trim??
The emissions are a pass so I am not thinking CAT??
My exhaust pipe at the back is black.
Any ideas???? Do I have a problem??