P0125 + P1135 codes, WTF ?

[hoiskii]

As the car was cold, it started abnormally (the sounds were like something is struggling in there to turn the engine and then at the first moment it sounded like a misfire or something). ... And the check engine came up. After 10-15 mins of driving the light went off. This happened already twice. The codes were P0125 and P1135. I understand the P1135 might be a broken O2 sensor heater, but how the P0125 can come up on the COLD ENGINE???? The car does not suppose try a close loop for a while, why does then the p0125 come up? By the way, the sensors work good, I have measured the voltage while the engine was running.

[dc_98_cam]

... can't pinpoint the problem with only this to go on. ... nothing obvious. Check Bank 1 Sensor 1 wiring and connection again.

See pp. 61 and 161 of the Diagnostic section of repair manual for relevant description of CEL codes.
Also some information on p. 55 ... is your car California spec?
P0125 is apparently fuel/O2 sensor related .... probably a secondary code and will go away when you figure out what the primary problem is.

Please edit your profile/signature ... include model/year and engine type, miles, etc.

[hoiskii]

Originally Posted by dc_98_cam

... can't pinpoint the problem with only this to go on. ... nothing obvious. Check Bank 1 Sensor 1 wiring and connection again.

See pp. 61 and 161 of the Diagnostic section of repair manual for relevant description of CEL codes.
Also some information on p. 55 ... is your car California spec?
P0125 is apparently fuel/O2 sensor related .... probably a secondary code and will go away when you figure out what the primary problem is.

Please edit your profile/signature ... include model/year and engine type, miles, etc.

Thnanks, it is a very good point to edit the profile.

Last time when I've changed the O2 sensor the car had ~75 kmiles and now at ~120 kmiles I'd not yet expect the sensor needs to be replaced again. Last time there was no p0125 code and I wonder this time it might be somthing unrelated like you said some contact problem. I'll go check tonight. The only "problem" will be the code did come up 2 times only and I have no way to reproduce for sure the circumstanses when it comes up, so all that trying will very likely take time....

[dc_98_cam]

The difficult start which you described may be a clue.

Even if you don't have a DTC code for it, unplug connector to the intake air temperature sensor, on the side of the air filter box, try to start the engine, and see if the cold start problem is better. If you have an ohmeter, and a thermometer, you can verify that the resistance across the IAT sensor terminals is approximately near the specified values .... maybe 3k ohms at 70F ... see p. 35 of Diagnostic section. ... Somebody posted a reference to this problem, recently.
Is it possible that you have a fuel pressure problem? .... Fuel pump, fuel filter?
No problem with your air filter or EGR?