Where is the o2 sensor located on a 2006 mitsubishi eclipse gt 3.8v6 sensor 1 bank 1

P0134 - O2 Sensor Circuit No Activity Detected Sensor 1 Bank 1
P0135 - O2 Sensor Heater Circuit Malfunction Bank 1 Sensor 1
P0053 - O2 Heater Resistance Bank 1 Sensor 1
P0030 - O2 Heater Control Circuit Bank 1 Sensor 1
You need to replace the O2 Sensor Bank 1 Sensor 1
Carquest can help you get the correct part and help you locate it.

If this is a V6 model, Bank 1 would indicate one side of the motor. Also, if it's the V6 model, I believe there are 3 O2 sensors, one per Bank, and one downstream(post-cat). If it is the V6 model, and it indeed is Bank 1, then just replace the O2 sensor, that's the most likely cause.

Give some more details of the problem.

it is not an O2 sensor but a heated oxygen sensor that is in the exhaust manifold before the cat converter
heated oxygen sensor(HO2S) 1 bank 1 is the one against the fire wall
it is not a heater as such but has an internal heating system so that it reads the exhaust emissions correctly and adjusts the air /fuel settings in the ECM
normally has 4 wires
the oxygen sensor (O2S) is after the cat converters and is a completely different sensor to read a different exhaust gas

Passenger side, after the catalytic converter.

It's the first O2 sensor that's in front of the catalytic converter. If it's a V6 car, it will be the one that's on the same side as cylinder #1.

have the engine light code scanned, and it'll tell you if it's bank 1 sensor 1, bank 1 sensor 2, bank 2 sensor 1, bank 2 sensor 4.

Bank 1 is on the same side as Cylinder 1
Bank 2 is on the opposite side of Cylinder 1

Sensor 1 is located before the catalytic converter.
Sensor 2 is located after the catalytic converter

if its a 4 cylinder it will the 02 sensor closest or if not in the exhaust manifold

it's right adjacent to the cataytic converter

Your question was truncated. I see that the bad sensor is on bank 1, but I can not see if it is the upstream (sensor 1) or downstream (sensor 2) sensor. The upstream sensors are mounted in the exhaust manifolds (look sort of like spark plugs) and have wires going to them.
You will need a 7/8" or 22mm wrench to remove the sensor (after disconnecting the wires). If your car has over 70,000 miles I STRONGLY suggest that you replace BOTH upstream sensors. One in each exhaust manifold.
Charlie