so i was driving and my check engine light came on so i ran the codes and i diagnostic it what throw the light was

Evaporative emission system large leak detected?

i found no vacuum line leaks. idk what the code means

diagnostic came back fine besides it said

htd catalyst N/A
sec air system N/A
a/c reff mon N/A
ERG system mon N/A

idk what those mean everything else came back ok

im new with reading codes and diagnotics

thank you for looking

 

Sorry but I can't help with the info you provided. Can you possibly post the numerical codes? That would make it easier to decipher their meaning, or possible cause.

 

engine was not running correct

 

http://donsnotes.com/home_garden/auto/dtc/evap.html

 

gas cap loose?

 

A loose gas cap OR a faulty gas cap is suspect for any evaporative leak code.

There are plenty of other possibilities, but start by verifying/replacing that gas cap.

As mentioned, always best to post the EXACT code number or numbers. With OBD technology, the devil is definitely in the details.