Are you running catalytic converters or not with boost?

[ben1]

Ben:
You won't see + or - 10% over time in fuel trims. You won't see anything, but a trouble code. If the front sensor was drifting that much.... How would it tell you that in a log via fuel trims, but not say the sensor is bad being that inaccurate?
Take it from Bugasu, Eco boost tuning guru nearly 10 years ago, if not from me.

My test wasn't just me theorizing what would happen. I logged actual results. I don't need to "Take it from" anyone else. And FYI the defouler system worked so with FAOSC ON it never threw any trouble codes and it passed ALL Emissions Readiness tests. This is why it continued to use the rear O2's to trim the fronts. And the test with FAOSC turned OFF proved that the front O2's weren't drifting on their own.

Sponsored

 

[WildHorse]

f you remove the cats the rear O2s will no longer correctly adjust for FAOSC.

Right, so you get a P0420/0430. I find it hard to believe that FORDS logic won't revert to some other routine. <I mean, you can drive along like nothings wrong, Do as many WOT hits as you want, etc.,etc , without consequences.

I've checked my logs religiously, checked my plugs, even my fuel economy is the same, trims are the same going on 4 years now.

So, after reading everything there is to read, the rears ONLY monitor cat efficiency, AND according to FORD, the rear O2's are only responsible for one half percent (.5%) of the fuel trims @ stoich.

 

[WildHorse]

So ran my 'other' tune which disables P0420/P0430 & FAOSC for about a month. Haven't noticed a darn thing different, other than CAT protection doesn't come into play.

 

[engineermike]

Ran across this on yt and it reminded me of this thread.

Does a Catalytic Converter Change Wideband Readings? (Dyno Tested)

Sponsored