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Old May 11, 2018 | 04:13 PM
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John Wygant's Avatar
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I haven’t modified an LS before, only maintenance. I just bought an ‘05 2500hd 5-speed 4x4 with a 6 liter, and want to remove the cats and put on a more open exhaust. Will it screw with my tune, like retard timing, lean/fatten the fuel parameters, etc? obviously the downstream 02 sensors are gonna throw a code that says the cats aren’t working if they aren’t there, but does it affect how it runs? (I don’t have to meet emissions)
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Old May 11, 2018 | 05:49 PM
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Originally Posted by John Wygant
I haven’t modified an LS before, only maintenance. I just bought an ‘05 2500hd 5-speed 4x4 with a 6 liter, and want to remove the cats and put on a more open exhaust. Will it screw with my tune, like retard timing, lean/fatten the fuel parameters, etc? obviously the downstream 02 sensors are gonna throw a code that says the cats aren’t working if they aren’t there, but does it affect how it runs? (I don’t have to meet emissions)
It shouldn't effect how it runs, as you said, it will only show a check engine light for the missing cats.
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Old May 11, 2018 | 06:50 PM
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Get your PCM tuned to ignore the missing 02 sensors after the catalytic converters and it won't turn the check engine light on for them being missing.

Rick
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Old May 14, 2018 | 10:09 AM
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Originally Posted by ss.slp.ls1
It shouldn't effect how it runs, as you said, it will only show a check engine light for the missing cats.
Thanks!
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