Ron Mullholand

My 2010 HHR with a 2.4 engine is throwing two codes po171 and 496 and I've already changed the evap canister solenoid what do I do next

firemangeorge

Welcome

The problem could be that you're writing the code incorrectly. It is P0171.
P codes are followed by 4 numerals (not a small case letter "o" like you posted)

Search the correct codes on this site and you'll see many related threads.
Be sure to set the Search window to Google Search.

donbrew

Usually means the EVAP purge valve (the one under the hood).

Oldblue

Welcome to the site,

P0171 code points toward a dirty MAF sensor, a cracked flex pipe or clogged catalytic converter per

https://www.obd-codes.com/p0171

I suggest you go systematically and look at one thing at a time, my money is on the flex pipe.

P0496 pertains to the evap Solenoid and or the evap canister
Per

https://www.obd-codes.com/p0496

donbrew

Well, not exactly. If the purge valve is stuck open (p0496 purge flow when commanded off) you can get a P0171 (too much air in the A/F). And hard starting.

The terminology used for the valves is very confusing, that's why I try to define which one physically. Sometimes the purge valve (under hood) is called the charcoal canister purge valve/solenoid and the other one is called charcoal canister vent valve/solenoid.

Oldblue

Im just pointing towards causes and solutions, check the flex pipe, test the under the hood EVAP Solenoid
If you can blow thru it , replace it.

aradmahogany

Are you running any sort of cold air intake system or have you modified the intake system in any way?