Weird Mode 6 Front-to-back Switch Ratio test for P0430

[MrCreosote]

NOTE: I'm using Forscan Lite and an approved OBDII adapter

Only have P0430

Compared downstream O2's and Bank 2 switching more often and also has greater amplitudes that Bank 1.
NOTE: Cannot compare to upstream since Wide Range A/F sensor and cannot find any parameter that switches.

Mode 6 Rear-to-front Switch ratio thresholds are from 0 to 600's for both banks.
Bank 1 runs about 500
Bank 2 runs in the 700's and fails.

QUESTION: To be clear: Is Mode 6 Rear-to-front Switch Ratio the parameter that trips P0420/430?

So I have two indications it is Bank 2 Cat Eff too low

This is a 2010 Escape w/Duratec 3.0 V6 where I'm pretty sure Bank 2 is the firewall engine side.

I put 2 18mm non-foulers on the Bank 2 aft O2 and the results are backward:
Bank 1 runs about 250 (huge improvement)
Bank 2 runs in the 700's (no change)

These results appear to be impossible - what am I missing?

Thoughts?

[DAN1000]

Bank 1 is the firewall side, Bank 2 is the radiator side, thats why your results are backwards.
Sounds like you bank 2 cat is toast, the spacers might fool the pcm into thinking the cat is still in limits

[MrCreosote]

Bank 1 is the firewall side, Bank 2 is the radiator side, thats why your results are backwards.
Sounds like you bank 2 cat is toast, the spacers might fool the pcm into thinking the cat is still in limits

I thought of this as I was trying to fall asleep last night and it was so obvious I couldn't fall asleep!

I just got off the phone with my garage friend and he confirmed that Ford engines in the past sometimes had #1 cylinder on the opposite side when compared to Chevy (and Studebaker, I'm a Studebaker nut - 18436572 is carved in stone in my memory), so I'm betting the Duratec has #1 cylinder on the "other side."

Thank you so much!
Tom

[DAN1000]

I've been in the Ford business for almost 50 years #1 has always been at that position on V configurations, at least in north america

[MrCreosote]

I've been in the Ford business for almost 50 years #1 has always been at that position on V configurations, at least in north america

Does that position correspond to being the first connecting rod on the front of the crank?

[DAN1000]

Yes & if you look at the block carefully bank 1 is shifted ahead of bank 2.
I believe that applies to all manufacturers