What scan tool special test do you run with a P0442 and P0496,

Question

and the data items a person would view with values that  should be, for GM cruze 1.4 turbo trying to find out what parts I need to replace to fix and eliminate the DTC set. thanks.....

Now got P0171 with long term fuel trim at 25 to 34% this happened the next day after trying to clear DTC p0496 and p0442 which were permanent

Perhaps the PCV problem that I been hearing about the 1.4 turbo engine

Answer 1

P0442 Evaporative emission system small leak detected

P0496 Evaporative emission system flow during non purge

Scan tool data, that would be the purge solenoid , and the EVAP vent data, With the fuel tank pressure sensor. This code that is set is a give away. If the purge is commanded off, and the fuel tank pressure sensor read a negative open the gas cap. if the Fuel tank pressure sensor still reads negative , the problem is the fuel tank pressure sensor. If the purge is commanded on . the fuel tank pressure sensor should go negative.  This is one way , there another look at the fuel trim with the purge in the off state. block of the purge line going to the fuel tank the fuel trim should drop . Another way and this is common. on the purge solenoid disconnect the quick connect going to the tank. (disconnect the power)  a good purge you should not feel vacuum on the line. plus when these purge go out sometimes you can even can hear a constant gluping noise from it when it is commanded off.