PO42O code???
#1
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PO42O code???
Catalyst System Efficiency Below Threshold (Bank 1)
is this the O2 Sensor going bad???
or is this telling me I may have a cat going bad???
code is from my 99 Yukon
is this the O2 Sensor going bad???
or is this telling me I may have a cat going bad???
code is from my 99 Yukon
#5
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Originally Posted by TouchOfEvil04
I fairly sure thats a cat code not a o2 code. Mine threw that for a while from the cats bein high flow so i had it turned off from the tune.
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Originally Posted by TXsilverado
the rear 02 sensors are what monitor the cats, so either way its an o2 sensor throwing the code...the real question is if its a bad o2 sensor or a bad cat. its a tough call since the o2 sensors like to go bad alot.
Swapping the o2's around would be the best way to find the problem.
#7
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Originally Posted by TouchOfEvil04
That is true. Didn't even think about it. But if they are stock cats they can go bad fairly easy as well.
Swapping the o2's around would be the best way to find the problem.
Swapping the o2's around would be the best way to find the problem.