2009 Aveo loses its mind between 55 and 60

[sumdumguy10]

So, the first trip of the day and only the first trip, when accelerating past 55 and before 60mph, the engine will sort of studder, then the speedometer will start to fall to 0, the gas pedal doesn't make the engine rev, and the two "fixes" I've found are, 1) rapidly hitting the gas pedal, but that only gives me a few seconds of power, and 2) putting the car in neutral (while still moving) turning the car off and back on then putting it back into drive. I've only had to do #2 more than once a few times to get it to work again. After that, let's say I make a 2 minute drive, park, get lunch, get back in and drive away, it doesn't have an issue. Even for the rest of that day. It doesn't matter if it sits for just a minute or hours, after the first trip, it's fine.

I've tried cleaning the throttle body, it had very little carbon build up, and it seemed to move just fine. Outside of that, I have no ideas.. it's an automatic, been well maintained for the most part. But because of the weird way it acts, because sometimes it doesn't do it (rarely), and of course it won't do it for a mechanic. It has good transmission fluid, good on oil..

It does have a light on, O2 heater circuit malfunction bank 1 sensor 2, O2 circuit no activity detected, HO2S circuit high voltage bank 1 sensor 2, HO2S heater control circuit bank 1 sensor 2. I've replaced both O2 sensors and didn't fix the issue(s). And it doesn't seem to bother the car after the first trip anyway. I did have to replace the header w/ catalytic converter, because the car had a code saying it was bad. But then these new issues came up. I've also replaced the TPS.

Over the years it's had a new ecu or two. Another weird thing, I don't think is related, is the digit clock on the dashboard never is correct, and seems to randomly forget what time it is and resets itself.

My theories are possible clutch/transmission issue, the TPS is bad or going bad, maybe a fuel system problem, and there is a broken wire somewhere (for the sensor issues)

I know that's a lengthy post, with more than one issue. But I'm more concerned about the weird loss of power than the sensor. But if anyone can help with one or both, I'd be extremely grateful!

[sjcleckley1]

I had a simular problem once going to work lost power would not accelerate and speedometer went to zero don't really know the cause but a lot of the sensors had cracked insulation at the connectors especially at the exhaust VVT solenoid valve and might had been shorting did this about 3 times replaced the conector with a replacement and made sure all the other wires were not touching and sealed the wires withe the rightstuff silicone to the connectors and has not happend since but think I did have a TB or Pedel code

[kcROB]

I had the same problem with my first Aveo, a 2009. I traded rather than deal with it. Later I discovered that GM issued a "driveability" recall on all Gen2 Aveos. The recall expired in 2012, but if you ask a dealer to research the number, it will list what was required to fix the problem. I remember something about the spark plugs needed to be changed due to a compatibility problem with the coil pak. The recall number is on the car fax I did before I bought the 2011. I will post it if I find the carfax. The original owner of my 2011 took the car in and had the GM recall satisfied.

[JamesBurke]

It's likely the downstream catalytic converter. It can become plugged if you've driven it with a misfire. I see you changed the upstream cat, but the downstream one is the one that strangling your motor. It will start and run fine, but then gets choked as the exhaust backs up. After it sits for a few minutes, it will start and run again for a short distance. I solved mine by running a large drill bit (5/8" x 1ft long) through the rear cat pipe from front to back. The catalyst is a soft texture, like volcanic rock, and gets plugged easily. Then it will run and not get plugged. This isn't legal in California, but it works most other places. BTW, on an Aveo you can also drill out the header cat, too. The penalty is that the O2 and cat codes stay and the CEL stays on. But you get used to it. Or you can spend the money and replace the aft cat, maybe about $200.