CEL

[JMA -997]

HELLO TO ALL!!!

I have just bought my very first PORSCHE! It is an '06 997 Carrera S. We installed 200 cel Cats and reworked the exhaust. Sounds great and runs real good. Funny thing is that the CEL come on on the 2nd time you start the car. It says open circuit heater O2 sensor downstream bank 2. We installed spacers to move the O2 sensor back.But the results are the same. The CEL light does not come on if we reset the ECU with a durametric cable or simply remove the battery leads. The CEL comes on only during the 2nd start up after reset. I now reset by removing the DME fuse and re fitting it before every start up. My question is this. Why does it happen and how to cure it. If i just ignore the CEL as the car runs fine with it on, will the ECU-DME go into Limp mode. Appreciate some help on this. :renntech:

[Loren]

:welcome:

Please tell all of your exact fault codes.

[JMA -997]

Thanks :thankyou: , but unfortunately its at the shop 500 mile away by sea. I will ask them to email me the printout. I should have read the codes but.... i only read the description on the durametric short list. And it said "heater bank 2 open circuit. It clears out, and the car runs perfect. But when I turn the ignition off and then restart the car, the CEL comes back on and the car still runs perfect. I hareset have installed the toggle switch to reset the DME at every start and the CEL doesn't come on. Question is what causes the DME to go on limp mode. I have known a few guys who removed the cats and ran the cars with no issues except of the CEL.

[Loren]

Without the fault codes everything is a guess.

Fault codes tell us exact what the DME thinks is going on,

[JMA -997]

Hello Loren! :D The shop sent me the codes and its is P0160-OXYGEN SENSOR AFTER TWC, BANK 2 OPEN CIRCUIT- HEATER. I hope this helps... Hope to hear from you soon!

[JMA -997]

i have tried resetting the DME using either the Durametric to clear the P0160 code or removing the battery for a few minutes. It will clear and wont come back. Funny thing is when I start the car up again it comes back on. All we did was replace the CATS with 200 cel per bank and reworked the exhaust. i don't really mind the CEL but my only concern is that it might cause the DME to go on limp mode. We checked the the heater resistance and it reads 2.4 ohms.

[Loren]

P0160 Oxygen sensor behind catalytic converter, open circuit

Possible fault causes

- Fault in the oxygen sensor heater, if this exists, is to be taken care of first

- Loose contact or corrosion in the connector

- Open circuit in the signal leads

- Open circuit in ground lead

- Oxygen sensor faulty

- DME control module faulty

[JMA -997]

Thanks! :thankyou: Now for the all important question...Will this (P0160) cause the DME to go on limp mode? Also why does the CEL clear out and only comes on during the 2nd start up after the engine is turned off?

[Loren]

No, it should not go into limp mode.

If the CEL is flashing the car should not be driven (or run) - driving with a flashing CEL can damage the catalytic converters.

If the fault is recorded in the DME in can in most cases also b e cleared if the fault does not re-occur or the conditions that caused the fault do not continue.

It would appear that you have an intermittent connection or sensor.

[JMA -997]

Whew!!! :thankyou: :notworthy: :renntech: I also remembered that when we redid the exhaust and cats, we needed to lengthen the O2 sensor wires a bit. Slightly thicker wires were used. We checked the continuity of the wires and found that these were ok. Could this cause the P0160 code? The CEL isn't flashing. I just reset the DME before every start by having a toggle switch before the DME. The CEL no longer comes on. At least now I don't need to reset knowing that it will not go into limp mode. Many thanks Loren.

[Loren]

I think you found your cause... :clapping:

[JMA -997]

:cheers: