I have a 2013 Duramax that of course has the stupid DEF, my check engine light came on Monday and Orielly's said the code it was giving was P21DD but there was no explanation...does anyone know what this means?
I have a 2013 Duramax that of course has the stupid DEF, my check engine light came on Monday and Orielly's said the code it was giving was P21DD but there was no explanation...does anyone know what this means?
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