My 2005 Chevy Aveo 5 is flashing engine light and stays on sometimes then flashes again .. Has a little miss fire and hitches on hwy .. hard on gss as well .. new timing belt installed already . any

SOURCE: 2005 Chevy Aveo - engine light and hold lights flash

I also had the same problem, But the problem lies in the switch the actual hold switch on my aveo there is a side entry way you can pop off the one on the left will give you access to the switch. what could of happen is theres is condensation in inside the switch. then when it gets cold it freezes causing the switch to malfunction. This could happen either by spilling something on the switch or using a cleaning solvent like armorall, YOU MUST BE CAREFULL WITH ANYTHING LIQUID NEAR THE HOLD SWITCH. Also the car going from warm when you drive then cold when you park it at night. My car was in warranty and remind you I came up with is the dealership had no idea what was wrong. they reseted the computer it worked for a week then was happening again. I have knoweldge in switches/wiring so i decided to check pot the switch and open it up and sure enough there was condensation took it to dealer told them to try a new switch works perfect and going on 5 months with out problems. Replacing the switch can solve pretty much every problem that is stated here i think. Also take a look at the wiring and connections for older aveos

SOURCE: Running rough check engine light on

cylinder 5 has a dirty or sticking injector. check pvc and egr valve.

SOURCE: check engine light is flashing and decreaased speed when acceler

Get a scanner on it to see what error the computer has found.

SOURCE: Check Engine light staying on in Chevy Aveo. Yes

Many things can cause this problem...unfortunately the only proven way to remidy this situation is to have your car scanned by a reputable mechanic with a diagonstic machine $40-$80. This will tell what exactly is causing the check engine light to come on, in the long run its much cheaper replacing whats wrong than trying to replace things that arnt wrong.

SOURCE: 2005 chevy aveo Check engine and hold light comes on only over 60

I've become SO FAMILIAR with this problem on my own Chevy Optra. The first time it happened, I took it in to my dealer. It cost me over $100 and I SWORE it would never cost me that again. It really IS the fuel system. (Sticking with Shell's "detergent" gas doesn't help!) Simple solution is to add a bottle of fuel SYSTEM cleaner (not just the fuel injector) and the FIRST sign of trouble or with each oil change. No more problems !! "Live and learn and pass it on !"