This is my first post and I'm sorry but I'm in need of a bit of advice.

I've had a remap recently (DPF and EGR delete, plus stage 1). I suspect that part of EGR delete remap has not been done 100% correctly.

Vehicle - VOLVO V50 2.0d 136bhp(turbo diesel) ECU - Siemens SID206

Since having the ECU remapped (I wont name names out of fairness to the guy who did it as he's been a gent so far) I've been getting the P0299 Turbo Underboost Fault code repeatedly. Under the recommendations of the tuner I've been chasing a boost leak for days which I just cannot find. I wasnt getting this underboost fault before the remap and the car was running fine. It's NOT going into limp and seems to be driving ok.

The tuner has suggested that he could just write the P0299 fault out of the ECUs vocabulary, but I'm not happy with this idea as it seems like a bodge job and I may need that fault alert in the future.

After spending 3 days chasing possible leaks sites, cleaning and checking sensors, I now suspect that the EGR delete has not been done properly. If the tuner has just deleted EGR error codes from the software and the ECU is still expecting some EGR gases as part of the MAF-MAP-EGR gas balance parameters will this contribute towards the ECU calculating lower than expected pressure at the manifold and therefore throwing up the underboost fault code ?

If the engine management system is balancing gases from MAF at the inbox, plus a mix of EGR gases and turbo boost gases at the MAP sensor, when the EGR is blanked out, shouldn't the gas parameters be rebalanced as part of the EGR delete??

Can anyone recommend what might have been done wrong so that I can go back to the tuner with some knowledge. Apologies for any misunderstandings or inaccuracies as I'm not a tuner.

Any help or advice would be great, thanks