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@nugget68 I think that's a wise move and you're on the right track. Whatever else you find will work better with good, new O2 sensors managing the closed loop system.
I fought misfires for lots of miles - and fortunately didn't toast my CATS. Maybe you didn't either. Hopefully!
It sure does. It tells me the Downstream O2 sensors (O2 1x2 and O2 2x2) are sensing exactly the same oxygen concentrations as the upstream O2 sensors. Ten minutes is long enough for the CATS to warm up to operating temp and start doing what they are supposed to do.
From those two facts, I think we can extrapolate that the CATS are doing NOTHING. lol ie: Shot!
It would look better if Graphs looked more like this:
I wouldn't say its normal for both to go bad together. The conditions that lead to their failure can be common to both, such as excessive flashing CEL due to misfires on both banks. I refer to ths Heading of this thread "Misfires sluggish at speed".
Your o2 sensors are ALL four clearly working. Your problem is NOT O2 sensor.
However - what we do not know (and IDK how to determine) if they are 'in calibration' as far as 14:7 to 1 equating to .45 volts. I still recommend (in addition to CATS), if you have over 100,000 miles on the O2's, I would replace them also. You will undoubtedly notice a marked difference in how your truck runs.
definitely going to replace the sensors, already ordered, should be here tomorrow... as far as the converters, I found Eastern brand that are pretty affordable, any thoughts on those? I have a welder and can do the work myself...
Wow, that puts a drastically different light on replacing CATS . I guess as long as they knock emission down enough to satisfy the "catalyst efficiency" test performed periodically by the PCM (won't set P0420 / P0430) I wouldn't care they were CARB compliant.
I would have worried about cost of having someone weld them in making them cost as much as all the others - that problem is solved for you.
after a little more research, I decided to go with the magnaflow 94136 cats, they have the bungs already welded in,so I just ordered them... now to decide if I want to keep the rear two or delete them...
Lol.
. I guess as long as they knock emission down enough to satisfy the "catalyst efficiency" test performed periodically by the PCM (won't set P0420 / P0430) I wouldn't care they were CARB compliant. 