you can just fix it up with some tools trust me
The P0155 refers to the Oxygen sensor on Bank 2, sensor 1. Bank 2 on your vehicle is on the passenger side of the engine. Sensor 1 is the first oxygen sensor in the exhaust pipe coming from the engine.
An O2 sensor can be purchased at any auto parts store.
the lamba sensor is located inside the maifold
The lambda sensor reads the oxygen in the exhaust stream.
It threads into the exhaust manifold on the back of the engine.
They can have problems related to corrosion because of the heat and the differences in metal between the exhaust system and the case metal on the sensor.
Check the O2 sensor(oxygen sensor) AFTER the catalytic converter
The oxygen sensor on a 2004 Volkswagen Jetta is located in the engine area. It is usually encouraged to warm up the engine so as to ease the threads.
The oxygen sensor on a Honda Civic is replaced by disconnecting the wiring harness and removing the sensor using a socket wrench. Anti-seize paste is applied to the threads, a new sensor is torqued into place, and the wires reconnected.
If the sensor is stripped you will have to replace it. If the fitting or hole it threads into is stripped it is likely you can make oversize threads and use a fitting called a bushing to repair it. Mind you I got desperate one night and epoxied one in. Its still working but if I ever have to change it I am toast.
The only thing you can do to them is change them.
you take it to the people to fix it.
Replace it. Sensor 2 is the one AFTER the catalytic converter.
Unfortunately there is no fixing an O2 sensor. If the "check engine" light is on due to an O2 sensor, it can only be remedied by replacing the bad sensor.
The oxygen sensor on a Saturn can be found in the exhaust manifold at the front of the engine. It simply unscrews and unplugs. 5 minute fix!
Disconnect the wires, and unscrew the O2 sensor. You might want some wd-40 to soak up the sensor's threads before you try to remove it.