my camaro barely wont pass smog i hooked it to my scanner and it says evap system iono i had a guy look at it an he said it might be the egr valve or something im not sure but its really annoying can somebody help to gimme different reasons and how to test them? its all stock so i have no idea

 

Provide full info on the car. Start with year. What does the exhuast look like? Cat(s)? How many miles? How does it run - start easy or hard, idle smoothly, any smell of excess fuel, misfires under heavy load, anyh possible exhaust leaks? What was the specific code? OBD-I and OBD-II have different codes, and different diagnostics, so we at least need that basic info. What does "iono" mean?

And, what are the results of the test? Provide passing limits and actual test results for HC, CO and NOx. What conditions are used for the test - idle, low load, moderate load, what RPM?

Might want to use the "signature" field, so basic info about your car - year, model, engine, tranny and the fact that it is totally stock shows up at the bottom of every post.