P0136 CEL 240sx, need help!

[Griiix]

1997 240sx
maybe someone here with O2 sensor experience can chime in.

Im getting a code P0136 O2 Circuit (Bank 1, Oxygen 2)

I replaced both my upstream and down stream O2 and the code is still there.
Upstream is Borsh and Downstream is NTK

What else do I need to look for?

[Ilya]

you are probably running rich! Check fuel pressure. Or a leaky injector

[brndck]

Did you clear the code after you replaced it?

[Griiix]

i disconnected the battery for like 15mins and hooked it back up

i didnt check the fuel injectors. but wouldnt that throw a different code?

[nissandrift!]

There could also be an open or short in the wiring, so double check that too.

[Griiix]

thanks mate ^

[Ilya]

There is nothing that checks the injectors for proper functionality. The software was not designed for that. I had an injector go out, car ran on three cylinders, and no CEL. The ECU uses deduction method, and that means you really dont know what it will do. Since you are getting O2 CEL that leads to fuel mixture, bad O2, electrical short. Now go and find out which one it is!

[Griiix]

Bad O2 : Fixed.
fuel mixture : not sure and hope its not.
Wiring : checking tomorrow


anyone have any idea if the connector or the wiring is messed up, how can i fix it?
the transmission is kinda in the way.............

[Griiix]

used OBD reader to delete the code.
came back after getting it cleared within 15mins.

im just thinking... could my downpipe be defective?
would that throw a P0136 code?

the OE down pipe i got was messed up... the O2 sensor broke and i had to get it tapped out and reweld a insert... could that screw up the reading of the O2?

i replaced my O2 with NTK 24545 which is specified for my car....
im starting to lose hope...... the wiring looks fine *to my understanding*

should i try and just get a new downpipe and test my luck?

[brndck]

Don't waste your time trying a different downpipe. Unless you have a crack in it or a blown gasket BEFORE the o2 sensor, it should have no effect on the fuel mixture the sensor is seeing.

[Griiix]

i checked everything. wiring. exhaust leak.......
the connectors look good. fucking a.

NTK 24545 oxygen sensor was replaced... what the fark

[Ilya]

Time to check the injectors and fuel pressure.