my codes are "P0452" witch is fuel tank stuff and the other was "P1870" witch is the Trans. slippage.i cant write the whole explination so big thing is are these code problems realy bad and need to get fixed or can i leav them?

thanks

 

Have a read through these - P1870 Explained and P0452 Explained

 

so are they important?

 

Wouldn't worry much about the P0452, but if left unrepaired, P1870 can lead to some severe problems with the transmission.