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Getting a P0420 code?

Old 04-13-2019, 01:18 PM
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2004 G35 coupe 6MT
Getting a P0420 code?

Getting a P0420 code. I know it means CC is below threshold, how do I tell if it's bad CC or o2 sensor. Also, could it be other things causing it?
Old 04-13-2019, 07:58 PM
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420 dude.

Pull your spark plugs and check them, also check for any intake leaks. OBD2 scan for LTFT threshold and if it's above 15% you've almost certainly got a vacuum leak, smoke test the exhaust for leaks.

If everything looks good you might have a catalytic converter starting to **** the bed.
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