Hi,
Got my 6.1 Challenger running great again, finally.
One issue, I noticed a P0420 catalyst efficiency bank 1 code.
Its boosted, so I have been expecting to have to deal with the cats and put in some hi flow as the exhaust manifolds and cats and mid-pipes are stock.
Does anyone know what the switching pattern should look like for the rear O2s when the cats are healthy on these cars?
Histograms for fuel trims ST+FT, and wideband eq ratio error are tight, bouncing around +/- 1.5 across the part throttle cells of VE...so I feel it is dialed in, on this car the front O2s are cycling maybe once every two seconds, but the rears look to be cycling too fast. I was expecting the rears to switch allot less often. I am noticing the rears switch almost as often as the fronts, although after the car warms up when idling or cruising at a constant speed the drivers side rear sensor just climbs up rich and saturates to the top of scale. It comes back low/lean if you coast (seems normal, since DFCO is enabled), then when I return to part throttle again the fronts start cycling normally... but the drivers rear maybe switches a few times before settling up to the rich side again. Does this sound like cat has gone bad?
I think this means the cats are not doing a good job as they should, so I probably need to put some high flows cats in? which brings up my last question... who makes a good quality high flow cat that survives behind a hemi running 9psi of boost?
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Originally Posted by jimmyZJ
