It's a 2009 SR5, 4WD.

From the ad: "Check engine light is on and says o2 sensor is bad, but replaced o2 sensor and CEL came back on."

In talking to them, they also cleaned the MFA and then replaced it.

Here are the codes:
P0171
System Too Lean (Bank 1)
P0174
System Too Lean (Bank 2)
P0138
O2 Sensor - Circuit High Voltage (Bank 1 Sensor 2)

I would take it to our mechanic, who is great, but that's who THEY took it to. So I'm at a loss. I would love to be able to buy it for my son whose car just died, but I don't want to buy into a problem vehicle.

Anyone experienced this and is there something that could be done? It can't pass inspection with the check engine light. Owners say it drives fine - just drove it three hours away and back with no issues.

Any help would be appreciated. Thanks!

If it will start and you can drive it without a problem and gas milage is within reason, i would start trucking.

Toyotas throw many codes some are important others just make a lot of money for part sellers and the people doing a lot of not needed work to fix a code item that really does not exist.

Thanks Ralph. Its more the issue of getting it registered.

And also, buying a car with an unsolvable check engine light doesn't feel great to me. I was hoping someone here might have had or seen or heard of a similar issue and could provide some insight.

How many miles? If you can't do the work yourself I would find a better mechanic. The factory service manuals are on this forum. If you follow the test procedures carefully you can find this issue. I recently found a broken wire for a wheel speed sensor after getting a few lights on the dash. I have tools though....and time to go through the process...and a lift....in a garage...BUT the manual was the key. One warning is that Toyota has a lot of "special" tools listed in their manuals. That's where this forum (and others) really helps because others have already figured out how to get around those usually expensive tools. Sometimes there are no alternatives...

O2 sensor codes? I’m still on the original O2 sensors on my 2005. I’ve owned it for 20 years(bought it new Feb 2005). From what I’ve read is that sensors should always be Toyota sensors, not some off brand or aftermarket. You can try and cheap out but lots of people have issues. I would make sure they are replacing them with OEM Toyota parts. The only parts that I didn’t go OEM are the front wheel bearings. Bought them from a forum member here that made them bolt on using Timken wheel bearings. Good Luck.

Usually title cannot transfer without a smog pass. A recurring CE will fail a smog test.
If you value the friendship I would walk away from this problem vehicle.
There are lots of well maintained vehicles for sale. Reasons for existing owners to sell are vast.
Keep looking, perhaps a Camry would be a safer and less maintenance demanding vehicle.