There's enough evidence at this point that deactivating the DFM isn't going to lower the fuel economy noticeably, it may even increase it.
So that begs the question, if this is the case WTF are the manufacturers doing it for? I thought it was for economy, could it improve emissions even if it doesn't save gas?
So that begs the question, if this is the case WTF are the manufacturers doing it for? I thought it was for economy, could it improve emissions even if it doesn't save gas?