P2106 P2110 P161B issues

[robbar]

Hi everyone, I’ve been trying to fix my niece’s Aveo. The P2106, P2110, and P161B codes have been causing the car to go into limp mode randomly for months now. I’m not a mechanic but I’ve done a lot of part-replacing on cars so I have tried to fix this car especially to help save money going to shops.

Some info: 2006 Aveo LT, 132K miles, spark plugs, cables, and valve cover gasket replaced 4 months ago, Engine light does not come on ever. Car was bought about a year ago at 126K miles. Battery was tested at Autozone, they said the battery was fine.

I started by looking up the codes online and found a lot of posts from people unsure what the P161B code was about. Most people asking questions about it never explained what fixed the issues. The very few who did explain said replacing the 3 vacuum hoses, specifically the MAP sensor hose, around the manifold helped fix the issue. I replaced those hoses and the car was fine for a few weeks but the codes and random limp mode came back. The connectors on the hoses were old and brittle.

I had a mechanic friend who cleaned the throttle body, while it was still attached to the car. It did not fix the issues and he suggested either the throttle body or gas pedal be replaced. But that wasn’t a guarantee and lots of posts from people with the problem said that didn’t solve their issue either.

I ended up just taking it to a Chevy dealer to get a better solution hoping they have encountered the issues before. They told me the ECM needed to be replaced for $690. I asked how they came to that conclusion and they said their OBD reader had trouble reading the vehicle and since the engine light doesn’t come on that the ECM was bad. Since nobody could afford that at the time I declined the repair. My friend suggested getting a junkyard ECM to see if it would help for now. I found a 2006 Aveo at a junkyard and took the ECM off of it. It matched my ECM and I swapped them. Besides the VIN being different, everything was the same and the same codes came back right away. The engine light still didn’t come on. So I figured either my ECM and the junkyard ECM were both bad, or they’re both fine and the clock display needs to be replaced for the engine light to show up and I don’t need to buy a new ECM.

Some other things to note: I did the idle relearn process each time I took off the ECM or disconnected the battery. Not sure if I did it right but it didn’t seem to make a difference. There was some corrosion on the negative battery terminal that I cleaned, but it didn't seem to make a difference either. Sometimes when the engine is struggling in that limp mode, I smell gas. The junkyard ECM did get a misfire code when the engine was struggling in limp mode but it didn’t come back after driving around. Old ECM is back on car with same codes again.

At this point I don’t know what to do exactly. I want to take it to another shop for another opinion but I also don’t want to have more money wasted on this. I’m hoping that someone on here has more experience with these codes and has a solution or just has better advice.

Thoughts or solutions?

[Eg.h2o]

Has this vehicle has this issue since she bought it? I assume she didn’t know the check engine light was blown when she bought it. Has the timing belt been replaced since it was bought? Has the compression been checked? If so what’s the psi in each cylinder?

[robbar]

As far as I know, it hasn't had the issue since it was bought. My sister bought the car thinking it was fine. I knew just by looking at it that some things needed repair or maintenance. Since the Engine light never came on, I assumed there were no codes. Until I checked it around April of this year and found those 3 codes along with misfire codes. The limp mode issue started happening around June, a few weeks after the spark plugs, cables, and gasket were replaced.

Timing belt has never been replaced since bought. I don't know when the Timing belt has last been replaced. I'm assuming it has been replaced before, after reading about how they need to be replaced more often than usual. I don't think the compression has been checked.

I don't know what exactly they did at the dealership to determine that it was the ECM. When I was supposed to pick up the car, they told me I would have to pick it up the next day because the mechanics were still putting things back together. When I picked it up, I asked why they thought the ECM needed to be replaced. They said because the engine light doesn't come on and their device had trouble connecting to the vehicle due to some power issue. It honestly looked like they didn't really mess with anything under the hood. Thanks for replying.

[Eg.h2o]

I doubt it’s an ecm issue, but I am thinking it could either be a timing issue ( thinking a cam may jumped a tooth somehow?) or a leaky injector possibly? Either one can throw things way out of whack and possibly give a fuel smell. I’m sorry that I don’t have any more ideas.

[robbar]

Well I doubt it's an ECM issue too. Last night I took out the clock display to see if there was a burnt bulb and found black tape covering the engine light display and the abs display. So that's why the engine light never came on. Engine light shows up now.

We're going to take it to a shop next week and see what they say. I'll bring up the possibility of a timing issue and or leaky injector. Hopefully this second opinion brings better results. Thanks for the help.

[robbar]

So I took it to another shop earlier this month. They told me they found codes related to the Throttle Body, Crankshaft sensor, and Camshaft position sensor. They did a Throttle Body relearn and correlation relearn, cleared the codes, and told me if the codes come back to bring the car back. I asked if the problems could be coming from the Timing belt needing to be replaced or if there's a compression issue. They said that's possible.

The original 3 codes came back driving home and I brought it to them the next day. They said that since the issue isn't happening when they test drive it that it should be driven more before being brought back. Those extra codes they found didn't show up. When I asked them what those extra codes were, no one knew and they said they didn't save them. They suggested replacing the engine because replacing the timing belt was a big job along with replacing the other parts mentioned earlier. I declined the repairs because they didn't tell me what the codes were and they didn't seem interested in solving the problem. Those extra codes never showed up on my Bluetooth code reader. The shop didn't charge me for anything so I just let it go.

My niece has the car back now because the temperature outside has gotten below 65 and for some reason the car does not go into limp mode when it's cold out, only seems to happen above 65. I don't know why this problem happens on hot days but it makes sense that the issue started happening in late May. The car will probably go to another shop next month when my sister and niece have more money. Hopefully they have better solutions.

Does anyone know what those other codes could be based of what they suggested replacing? Any of this sound familiar to anyone? Can anyone help any further?