2014 Mustang 5.0 Lambda Rich After 7000rpm

[mejohn50]

I am VERY new to tuning gas engines and brand new to the Ford Coyote platform. I have a 2014 Mustang GT that is stock except an off road mid pipe. I started with my stock tune and referenced LaSota's book and other tunes, I put together a very basic tune for my car. No spark changes other than pulling a couple degrees out of the OP MBT table for the time being. I made some of the other changes LaSota's book suggests, but nothing crazy, and a few low speed transmission drivability changes.

WOT lambda is set to 0.820 across the board right now as I try and get some baselines to see where spark is currently at and where I can improve while I figure this thing out. When It crosses the 7000rpm barrier, the O2s start reading 0.78 lambda. Why is this happening? I honestly have no idea where to look.

Thanks for any help.

Mitch

Tune - OR Mid v1.4.hpt
Log - v1.4 WOT AAFES 91oct.hpl

[kris5597]

It's the cat over temp protection.

[mejohn50]

It's the cat over temp protection.

Ah hah! Thanks for looking at it for me. Now, the next question: Does it makes sense to disable all that or raise the temperatures as I already did? I see tunes either way, just wondering what makes more sense. At this point I am thinking disable all of it...

Thanks again.

[Blazin72]

You don't need Cat Overtemp if you don't have cats.

[mejohn50]

You don't need Cat Overtemp if you don't have cats.

That makes perfect sense. But, can anyone explain why some tunes don't have that stuff disabled, just the temps raised, even though they are tuning for a car with not cats?

[txcharlie]

That makes perfect sense. But, can anyone explain why some tunes don't have that stuff disabled, just the temps raised, even though they are tuning for a car with not cats?

I believe it's an oversight by the tuner. With Cat overtemp enabled, the car will run very rich in order to cool the cats. Like Blazin said, you don't need it if you don't have cats.

[kris5597]

It's the difference in tuners. Some prefer to utilize factory functions and some disable. Works the same way with the torque limits. There's no wrong way, if tuning it in the correct manor, just preferences. I have stock cats but have chose to disable the over temp protection. I feel the car runs rich enough anyways, running the same AFR at WOT isn't going to cause a problem, unless, I'm constantly beating the hell out of the car raising EGTs. The tuner should tune to the driver and what the car will be enduring.

[mejohn50]

Thanks for all the help on this.