Cadillac Catera (1998) Replaced Bank 1 Sensor 1 and Bank 2 Sensor one, codes P0135 AND P0155. Check Engine light came right back on Replaced ECM, 13 miles later the light is back on, replacing the aftermarket sensors with Factory ones from GM because the aftermarket sensors aren't working, Any ideas?

If they are codes P0135 and P0155 they refer to both O2 sensors nearest the engine on the exhaust. The ones before the catalytic converter on each exhaust pipe.
P0135 = O2 Sensor Heater Circuit Bank 1 Sensor 1
P0155 = O2 Sensor Heater Circuit Bank 2 Sensor 1

Here's a link for codes P0446,P0443. https://www.obd-codes.com/p0446 Here's the link for P0403. P0403 Exhaust gas recirculation EGR circuit malfunction Here's code P0135 P0135 OBD II Trouble Code O2 Sensor Heater Circuit Malfunction Bank 1... Here's code P0141 P0141 OBD II Trouble Code O2 Sensor Heater Circuit Malfunction Bank 1... Here's code P0155. P0155 OBD II Trouble Code 02 Sensor Heater Circuit Malfunction Bank 2... Here's the last code.yay P0161. P0161 OBD II Trouble Code HO2S Heater Circuit Malfunction Bank 2 Sensor 2... The last 3 codes might just be one sensor.

all of those codes listed have a common fault listed and that is the ECM
substitute it with a known good unit and then see what happens

Which engine ? Some have four and always double check the connections as they can set the codes .

You can not work on a vehicle as your doing

Your checking for generic codes only & throwing
parts at it

You get a couple possible worn or failed parts & have
a few less codes

There is no need to clear ALL Data every time you change a part

You need to STOP

You need professional scan tool software to look at ALL data & go for a road test first

You keep clearing stored data ,so now the process will take longer

You work one code & one system at a time

NO PARTS get replaced that are not tested & found to fail
a test,thus a worn out part.

You need both Factory Emission & Diagnostic Manual, as well
as Wiring Diagram Book-- BEFORE-- you can even walk to the vehicle (Helm.Com)

You have nothing to go by,no system knowledge & no trouble charts,& no wiring diagrams to start your testing

If you got no scan tool & no volt meter & no oscilloscope,
your done,vehicles have to be tested to find a problem,any
problem,resolve it & continue on.

kia ora Mark , greetings , sorry bro these code things are beyond me ive been driving around with a p0161. i believe its a bank2 down stream sensor for 2 years , maybe you can help me , 2002 grand cherokee 4.7 Ho , do you know what brand of sensor or part numbers i need , an idea of cost for same . i forgot to mention i am in New Zealand and auto parts are so much more expensive here , no idea at all , much help needed everyone thank you all , hope you get sorted Mark cheers mate

Hi there:

DTC P0125 - Insufficient Coolant Temperature For Closed Loop Fuel Control

The simplest thing to do is to reset the code and see if it comes back.
If the code comes back, the problem is likely going to be the result of the above causes (faulty thermostat, faulty ECT sensor, or a low coolant level).


DTC P0135 - Oxygen O2 Sensor Heater Circuit Malfunction (Bank 1, Sensor 1)
or
DTC P0155 - 02 Sensor Heater Circuit Malfunction (Bank 2 Sensor 1)

A code P0135 and P0155 may mean that one or more of the following has happened:

• O2 Heater element resistance is high
• Internal short or open in the heater element
• O2 heater circuit wiring high resistance
• open or short to ground in the wiring harness

In order to solve just...

Repair short or open or high resistance in wiring harness or harness connectors

Replace oxygen sensor (cannot repair open or short that occurs internally to sensor)

Hopoe this helps.

Here are the reasons for that code:

HO2S no. 1 heater circut is open or shorted
HO2S no. 1 is defective
Defective ECM

Using a scan tool, read freeze frame data. Freeze fram data records engine conditions when a malfunction is detected.

Access ECM behind glove box. Turn ignition on. Using DVOM, backprobe ECM harness connector. If DTC P0135 is set, measure voltage between ground and terminal No. 3 (Blue/Black wire) at ECM harness connector E10. If DTC P0155 is set, measure voltage between ground and terminal No. 4 (Yellow/Red wire) at ECM harness E10. Voltage should be 9-14 volts at each terminal. If voltage is as specified, replace ECM.

If not, Disconnect suspect HO2S No. 1 harness connector. Measure resistance between terminals B+ (Black/Yellow wire) and HT (Blue/Black wire on bank No. 1 ; Yellow/Red wire on bank No. 2) at HO2S connector (component side). Resistance should be 11-16 ohms at 68 degrees F and 23-32 ohms at 1472 degrees F. If resistance are not specified, replace appropriate HO2S. If resistance are specified, Repair wiring between ECM and appropriate HO2S, or between appropriate HO2S and EFI main relay (Black/Yellow wire at HO2S and Red wire at EFI main relay)

with those codes showing, it could be either bad O2 sensors or there is a problem with the wiring to those sensors. Also, the wrong sensors may be installed. I'm assuming codes P0134, P0135, P0155.

For others viewing this:

P0134 = O2 sensor circuit-no activity detected (bank 1 sensor 1)

P0135 = O2 sensor heater circuit malfunction (bank 1 sensor 1)

P0155 = O2 sensor heater circuit malfunction (bank 2 sensor 1)

you say you replced sensors but some times that code could be also be the o2 sensors you should have 2 maybe 4 did you check them