Annoying Aveo!

[PatF]

Hi and thanks for your rely.
There are no fault codes showing, which makes it more of a mystery!

[joniko]

You're welcome. I understand what you mean about the mystery;no check engine light does seem mysterious. I don't want to frustrate you with unnecessary input but the problem must be out of the computer's monitoring system or undetectable,(they tend to throw codes at the slightest sign of trouble). It may help the forum to diagnose the issue if you can add to your description of what the car is doing. What sounds can you describe? Intake leaks and vacuum lines make a distinct noise(hissing). You can check for such leaks with a spray bottle with a little dish soap in it, there are many youtube videos on that. This post probably did little good but don't give up on it yet. Be patient and you will work it out.