Question

2005 Chevrolet Aveo 1.6L with engine codes P0420 and P2279, and with rough idle

Answer 1

Hi Tony

The P0420 code may be caused by unburned fuel. If you have a rough idle I would first check for intake manifold leaks and take a good look at the spark plugs. If these come up good, then I would drop the front pipe and look at the catalytic converter. It may be partally blocked or broken and causing the code and the problem.

Answer 2

P0420 CHEVROLET - Catalyst System Low Efficiency Bank 1
Read more: https://www.autocodes.com/p0420_chevrolet.html

P2279 CHEVROLET - Intake Air Duct Air Leak
Read more: https://www.autocodes.com/p2279_chevrolet.html