I'm not worried about the environmental/legal issues. I'm not too worried about the cel being on all the time. Do I need to do anything to protect my engine at this point? Thanks!

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    not really. you might put anti foulers on the rear o2s and see if you can turn off the MIL.
    – Ben
    Aug 19, 2016 at 11:48
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    You can buy a product to simulate the catalytic converters being present so the computer doesn't freak out... urdusa.com/store/Electronics-Rear-Sensor-Simulator/c66_170/…
    – cory
    Aug 19, 2016 at 13:44
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    @Ben I agree - I've also seen them called 'non-fouler' extensions. @ OP I would recommend you get rid of the CEL, otherwise you'll never know if it turns on for a different problem (injectors, timing, airflow sensors, temp sensors, imminent spontaneous combustion of occupant sensor, etc.) Aug 19, 2016 at 15:00
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    @MooseLucifer - Absolutely agree ... full heartedly! Aug 19, 2016 at 17:08
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    +1 on @MooseLucifer's point, you want a functioning CEL, as it warns you about changes in the engine's health. Beyond setting the CEL downstream sensor might be "tweaking" the engine's behavior in ways that aren't optimal. Tuners are likely to be able to tell you what consequences to expect.
    – dlu
    Aug 19, 2016 at 22:23

1 Answer 1


If you're not worried about the check engine light (which will more than likely turn on since the 02 sensor will be receiving an excess amount of exhaust reaching it now) or environmental considerations, then removing the cat won't cause any harm to your engine. Some people even believe that driving without a catalytic converter allows the engine to breathe better and utilize more of its horsepower. Be warned though, there are typically laws in place that say a car must have a catalytic converter.

  • "Be warned though, there are typically laws in place that say a car must have a catalytic converter." Not if it didn't originally come with one.
    – Glen Yates
    Sep 7, 2017 at 14:09

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