Yabbe

I received a m/t civic from my friend, and managed to fix everything wrong with it except this problem. I am getting P0135 and P0141 error codes.

What happened so far:
Car is suppose to have two sensors, a 4 wire and a 5 wire, but when looking at it the 5 wire was spliced into a 4. I ordered denso replacement for both of them. When I got them I put the 4 wire on and both codes were still being thrown. I then undid the 5 to 4 splice and wired it how it should be. I still received the codes after this.

Notes:
Fuse 15 is not blown.
CEL was reset everytime I went to test it, using bluetooth adapter + torque.

What is left:
Electrical measurements with multimeter.
I have no other ideas.

Why am I here?
I would like to know if anyone has any ideas on what the issue could be. I have no experience with using multimeters and therefore am completely lost on what steps to take. Any help would be appreciated, I have been at this for awhile now. The car runs fine, I just can't get it smogged until I fix these CEL'S.

Former User

1) Check what ECU the car has.

2) Check whether the engine is the stock D16Y5 or a swap. Verify by posting the block and head codes.

Yabbe

1)
d16y5

2)
37820-P2P-34921-324574

I see. Can I swap a P2M into a system that was modified for a P2P or will modification need to be done?

Former User

I assume this^ is the block code. What's the head code?

https://honda-tech.com/honda-civic-d.../#post48684945

Yabbe

My bad.

Head code: P2J3

Former User

Okay. You have a D16Y5 engine connected to a D16Y8 ECU. If you want to use the Y5 engine, you need a P2N ECU (for manual transmission) and a 5-wire primary O2 sensor. You also want to check whether the Y5 EGR system, IM, and TB are still present.