the rear O2 sensor has no impact on fueling, it is there purely for monitoring cat performance. On standard software it is very unusual not to have the MIL light on due to the rear sensor not having a cat in front of it..

There is the possibility of the turbine end turbo seal letting a bit of oil through now the exhaust backpressure has been reduced, the backpressure assists the seal in keeping oil in, although a good condition seal is unlikely to be an issue. Hard to see why the fueling should be drastically altered due to cat removal, apart from the reduced backpressure altering the base fueling a tad due to freeing up the turbine flow, under light cruise condition the front lambda sensor should pull that back in.

the rear O2 sensor has no impact on fueling, it is there purely for monitoring cat performance. On standard software it is very unusual not to have the MIL light on due to the rear sensor not having a cat in front of it..

There is the possibility of the turbine end turbo seal letting a bit of oil through now the exhaust backpressure has been reduced, the backpressure assists the seal in keeping oil in, although a good condition seal is unlikely to be an issue. Hard to see why the fueling should be drastically altered due to cat removal, apart from the reduced backpressure altering the base fueling a tad due to freeing up the turbine flow, under light cruise condition the front lambda sensor should pull that back in.

Right well read my last post now before yours???

I'd suggest speaking with Nich at R tech tomorrow as you might need to get a new sensor ordered.

delete.. double post..

Edited 20 March, 201115 yr by richm

Right well read my last post now before yours???

?? not sure what you want me to say? everything I said still stands.. you possibly have a damaged front lambda sensor which is upsetting the fuelling, get some diagnostic kit on and read the target and actual lambda data (block 031) and compare with readings from an independent lambda meter or gas analyser at the tailpipe.

Turbo is gone boys only 3 weeks old the guy I bought it from is on hols for 3 weeks???? I have aa warrenty so there on the way I will het a new one for £25 through them...