2009 Aveo Low Compression

[Joe021]

Hi all

This is my first time posting here as I just bought a 2009 1.6 L Aveo from an auction. When I got the car it had oil in the water, low compression, as well as a P0017 code. The compression in each cylinder was 135 135 155 which I found strange. Anyway I bought a new timing kit and replaced the timing belt. I pulled the head and replaced the head gasket which was warped .007 in. After I put it all back together I rechecked the compression, none of the cylinder psi had changed. I did a wet test and a slight increase in psi, about 5-10. Does that mean the rings are bad? I currently have codes P2101 and P0420. Any advice would be great because I am stuck.

Thanks

[2010AveoLT]

P0017: Crankshaft/Camshaft position correlation Bank 1 Sensor B error
P2101:TAC (Throttle Actuator Control) Circuit Range/Performance error
P0420: Catalyst below minimum efficiency threshold (and your wallet is about to be MUCH emptier as a result)

I have had no luck on finding a compression specification.

[Joe021]

I fixed the P0017 code when I replaced the timing belt. The car has been sitting for a while. Could that cause the P0420?

[2010AveoLT]

I fixed the P0017 code when I replaced the timing belt. The car has been sitting for a while. Could that cause the P0420?

how long has it been sitting? (my car sat for a month about 3 years ago, and the P0420 JUST showed up for me)

[Joe021]

At least a month, and who knows how long at the auction.

[jamesd]

I fixed the P0017 code when I replaced the timing belt. The car has been sitting for a while. Could that cause the P0420?

Many things could cause the P0420. Anything from a plugged catalytic converter to a damaged rear (downstream) O2 sensor. I would checks the wires and connectors to the O2 sensor. Also I would check any exhaust leaks or damaged to pipes too.

[Joe021]

OK I will do that later. Do you have any idea what the compression should be? I cannot find the spec anywhere. The only thing I have found is that no cylinder can be more than 15% off from the cylinder with the highest psi

[jamesd]

When you found out that the cylinder head was warped, did you have it machined or replaced? If it was me I would go as far as doing a leak down test as well just to cover all basis. I know a friend who had a compression tester that was giving wrong readings. He did a head gasket job and still had the same low compression readings. He tested it on another known good engine and it read that it had low compression levels. Needless to say the tester was bad. It may not be the case in your situation but just a thought.

[Joe021]

I got it pressure checked and machined. I have done the leak down test with no leaks detected.

[Joe021]

So here is what I have now, my car is throwing both p0011 and p0014. The car drives relatively well and has no loss of power nor does it have a rough idle. All it has is a slight rpm surge or variation under certain conditions, as in giving the car a certain amount of power. Does anyone have any ideas? I don't think timing belt or camshafts are incorrectly aligned.