The 606 uses Bosch EDC12 right? Or is it EDC15? In any event the MAF is used to see that the EGR is working, and to limit smoke.

If they are EDC 15 you should be able to tune out the EGR and get MAF delete if you so choose. If your tuner can't do that I'd suggest finding another one.

-J

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1991 350SDL. 230,000 miles (new motor @ 150,000). Blown head gasket

Tesla Model 3. 205,000 miles. Been to 48 states!
Past: A fleet of VW TDIs.... including a V10,a Dieselgate Passat, and 2 ECOdiesels.
2014 Cadillac ELR
2013 Fiat 500E.