2000 Solara "Air Fuel Ratio Sensor" malfunctions

[misterEE]

Hi All...First time posting here. I got a Check Engine light, took the 2000 SLE to the dealer (before I knew about OBD scanners), and was told the right and left air fuel ratio sensors had failed: $106 please for the diagnosis. They ordered the parts and I brought it in for the repair, only to be told some hours later that only one had been replaced (another $536 between part and labor), but that the 2nd was "frozen" in place, due to high heat exposure, and that in order to replace it, they'd have to also replace the exhaust manifold (?) and gasket it sits in ($900 plus for this, I'm told). Can anyone tell me whether this is a common problem, and complication, as I'm being told? I know you're not looking at my car, but any possible insights would help. I'm up against a CA smog check deadline, and it won't pass while the Check Engine light is on.
Thanks!

[toyomoho]

The sensors can get stuck. Which sensor?

Try PB Blaster a penetrating fluid and letting it work overnight.

Or find a shop that can try applying a little heat to the sensor and manifold from a torch.

Any shop should be able to work on the car and replace the sensor. Suggest using Denso or Toyota OEM brand to prevent possible issues with the CEL coming back on.

[new echo owner]

Did they give you the stored codes? It is unusual for both to fail at the same time, possible but unusual.

N.E.O.