PE tuning with wideband o2 question

[S2002S]

I set my VE table using the procedure defined in the sticky in this folder and left the MAF table stock. I'm trying to adjust the air/fuel ratio at WOT but modification of the PE multipler vs RPM table does not seem to affect the outcome. As an example, the Fuel/Air multipler reads 1.25, AFR command reads 11.7 for a PE table value of 1.2. I seems to me that the commanded AFR should be about 12.25.

How much of a change to the PE table is typically required move from and A/F ratio of 12.0 to 13.0?


Thanks!

Brad

[jimmyblue]

There are other enrichments which might command
a 1.25 Fuel Air Multiplier (which is the PID you may
want to look at instead of commanded AFR since the
PCM works on FAM pretty much). The highest of all
enabled enrichments "bids" wins and that's what you
get. Cat Overtemp for example likes to slide on up to
1.25 if it gets woken up. PE value may or may not be in
charge.

[S2002S]

Thanks jimmyblue, I'll check the cat overtemp. Any other contributors?

[S2002S]

Well, the problem definitely was the COT. It was pegging on the max enrichment value.

Does anyone know how the PCM determines the COT condition? If anything, I'd expect a low temp on the cats since they have been moved behind the longtubes.