1998 Infiniti I30 trouble code P0134 were are the oxygen sensors?

Question edited for clarity and toss in some CAPS.

There is nothing that backs up memory. When you disconnect the battery, all memory is lost, which is why it is important not to do it!

You don't tell us the model? Is it a secret? All questions need 'year make model' as the FIRST 3 words.

If your have a 1999 Infinity I30, the ECM Fuse is Fuse 58.

58 10 Engine Control Module (ECCS), Mass Air Flow Sensor, Crankshaft Position Sensor, Idle Air Control Valve (IACV-ACC) Solenoid Valve, Ignition Coils, EGR, EGR Volume Control Valve, EVAP Control System Pressure Sensor

Infiniti i30 (A32; 1995-1999) fuses and relays

Fuse Box Diagrams https://fuse-box.info > infiniti > infiniti-i30-a32-1995-...

Fuse box diagrams (location and assignment of electrical fuses and relays) Infiniti i30 (A32; 1995, 1996, 1997, 1998, 1999).

Infiniti i30, i35 (A33; 1998-2004) fuses and relays

Fuse Box Diagrams https://fuse-box.info > infiniti > infiniti-i30-i35-a33-1...

Fuse box diagrams (location and assignment of electrical fuses and relays) Infiniti i30 / i35 (A33; 1998, 1999, 2000, 2001, 2002, 2003, 2004).

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Which O2 sensors came out of the vehicle an which did you put back in ? Two different types for that vehicle.

DTC P0134 or P0154 (w/LR4 and LM7 w/ Delphi HO2S)
DTC P0134 or P0154 (w/LR4 and LM7 w/ Denso HO2S)
DTC P0134 or P0154 (w/LQ4 w/Denso HO2S)

Help in the link

P0720 2000 INFINITI I30 Code Vehicle Speed Sensor

https://www.autocodes.com > p0720_2000_infiniti_i30
Diagnostic trouble code is detected when Transmission Control Module (TCM) does not receive the proper voltage signal from the sensor. 'What are P0720 2000 ...
Missing: miss ‎' Must include: miss

More here

https://www.google.com/search?q=2000+infiniti+I30+miss+shifting+code+P0720

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code p 0134 refers to heated oxygen sensor(HO2S) 1 bank 1--no activity detected ===causes wiring open circuit ---heating inoperative ---HO2S Sensor
also refers to oxygen sensor (O2S) --no activity detected ===causes --- wiring---O2S
the HO2S is in the exhaust manifold before the cat converter
the O2S is after the cat converter
check the wires and connections , then replace either or both sensors

As you have probably discovered, the diagram isn't included in the
Owner's Manual (http://www.downloadcarmanuals.com/1997-infiniti-i30-owners-manual-download) or even the service manual (Infiniti I30 and I35 Factory Service Manuals NICOclub).
It looks like the layout is the same as the Maxima from that era:



The 1998 layout is the same, although I'm not sure whether the actual lid/door will fit-
98 1998 Infiniti I30 Gray Fuse Block Cover Lid Door Panel Bezel OEM M88...

98 1998 Infiniti I30 Fuse Block Cover Lid Door Panel Bezel OEM 68964 eBay

Oxygen sensor can give trouble because of many factors, but usually they get faulty at certain mileage, as to camshaft position sensor this can have only few problems: one is when the belt jumps a tooth, another when the wiring gets loose, and final if the sensor reaches its operational mileage.

Sensor 2(s) are those aft of the catalytic converter(s).
The pre-cat sensors typically fail more frequently than those post-cat.
The codes you cite are related to all sensors.
It is worth running a test of the sensors. Most garages can do the tests without any disassembly and for less than the cost of replacing any one of the four. Then you can replace the faulty unit with confidence.

Both codes are for the oxygen sensors.
P0134 oxygen sensor on bank #1, sensor #1 is bad.
P0420 oxygen sensor on bank #1, the sensor down by the catalytic converter, is also bad.

P0108 - Manifold Absolute Pressure (MAP) Sensor Circuit High Voltage,
Possiable MAP sensor defective

P0134 - Heated Oxygen Sensor (HO2S) Circuit Insufficient Activity Bank 1 Sensor 1
P0141 - Heated Oxygen Sensor (HO2S) Heater Performance Bank 1 Sensor 2 , I recommend you replace both O2 sensors, bank 1 and bank 2

it under intake goood luck