If I remove the Cats on an E46 M3, do I need the O2 sensor simulators? Or can I just remove the cats and call it good? I know many places sell O2 sensor simulators for the E36 M3 and other cars, but I haven't seen anything for the E46. Thanks!
NASA Arizona/SoCal - TTC #72
You can do that and call it good. The car will eventually throw catalic converter ineficiency codes which will trigger the SES light, but not a biggie imo.
Current:
Alpine White E46 325i Touring S54 6MT
Titanium Silver E39 540i Touring M-Sport S62 6MT
Past:
Alpine White E46 330i ZHP Sedan S54 6MT
Interlagos Blue E85 Z4 M Roadster 6MT
Le Mans Blue E92 M3 6MT
Japan Red E46 325i Touring S54 6MT
Estoril Blue Individual E46 M3 Coupe 6MT
Cosmos Black E36 M3 Coupe S54 6MT
Alpine White E92 M3 6MT
Alpine White E90 M3 6MT
Laguna Seca Blue E46 M3 Coupe 6MT
Jet Black E36 325is S52 5MT
Lagoon Green E36 325is 5MT
I disconnected my secondary O2 sensors when I put in my headers.
You can always get a Conforti Shark set up for Euro headers and no cats. If you gut the cats on the US S54 motor, this is essentially what you end up with.
When the second 02 sensor is left in place with no cats, the ECU will not see the proper voltage variation between the forward and rear O2 sensors. It throws a fault code because it does not know whether something is wrong with the cat (remember, the ECU thinks it is still there) or the O2 sensor. In other OBDII vehicles, I believe that the ECU reverts to closed-loop mode for the O2 signal and just starts using default maps to help control the A/F ratio.
Shark Injector or D/A Race program would be a more comprehensive work-around.
Hi,
What did you learn concerning the Cat converters?
Is it safe to just remove the Cat and dissconect the post cat O2 sensors?
Thanks
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