[ELMEPRO]

Hello, car has two faults:
12ab04 oxygen sensor after cat electrical line disconnection
12b701 oxygen sensor after cat internal resistance to high

replaced lambda still have two faults

my main suspect is maybe car is tuned?

if i delete faults, recycle ignition no faults, start car no faults, after 1min one fault sometimes 12ab04 sometimes 12b0701

lambda functions ok and are enabled by looking on real data even is check engine on and those two faults

but no check engine, but i car id derived 20km check engine on with those two faults

E90 335 (N55 engine with mevd17.2 tc1797)

what you think guys?

[m1ke]

Tuned car should not make faults related to wiring.

After replacing did you check the fuse for lambdas? Maybe has blown?

If not that you need to do harness checks...

[ELMEPRO]

Tuned car should not make faults related to wiring.

After replacing did you check the fuse for lambdas? Maybe has blown?

If not that you need to do harness checks...

Thats the problem there is no problem with harnes eather fuses they work but fault codes are still active sometimes

[Isooow]

Change sensor after cat, job done or delete DTC from ECU. A tuned car can not trigger faults related to electrical faults

[ELMEPRO]

Change sensor after cat, job done or delete DTC from ECU. A tuned car can not trigger faults related to electrical faults

i already replaced it that's why im asking for help, looks like i will delete faults from ecu, because i dont see problem in connector, wires..

[TilQ34]

Had similar a time ago. After changing(brand Delphi) and some km´s the DTC came back, engine running good.
After clearing DTC and some road the DTC came back, engine running good.
Replaced with another new, brand Bosch, has been 2 months and no issue/DTC anymore.

**Car had Burbles programmed since a year.

[ELMEPRO]

Whell, i end up just deleting fault codes from ecu, but now im facing a new problem can pass exhaust pollution test i have co % 0.460 and CH ppm 297 at lambda shows as 0.99

[m1ke]

Sounds like it has no catalyst… can you remove second lambda and use borescope to check?

[ELMEPRO]

Sounds like it has no catalyst… can you remove second lambda and use borescope to check?

it has a cat, to change lambda on this car need remove cat completely

[m1ke]

Sounds like it has no catalyst… can you remove second lambda and use borescope to check?

it has a cat, to change lambda on this car need remove cat completely

Ok, any missfire codes or counters going up?