Check engine codes 335, 172 help me

[jcbkid]

i have a code 335 which i think means egr out of signal so what do i replace?

and i have a code 172 i have no idea what it is so please let me now what to fix

 

[dmac0923]

p0335 is "Crankshaft Position Sensor" A Malfunction

this is a simple fix. find and replace your CPS

P0172 is "Bank 1 Too Rich" this is a general trouble could. could be caused by leaking intake manifold gaskets, or a bad MAF sensor