Front Bank STFT Maxed out Rich-Suggestions

[Greg E]

I keep seeing STFT being confused with LTFT low in this thread...

LOL! Got me there.

[NOMIEZVR4]

Anything under 100hz is the low trim. Usually that's idle.

Few questions:

Do you have periphery 0 bit 2 disabled? NO
Does the front sensor cycle while cruising? YES, I can go for a drive and double check, but im certain it does.
Hotwired fuel pump with the stock FPR? YES

.......

[Greg E]

Next can you confirm that you are getting 12V at the fuel pump? Talking about actually using a volt meter and measuring at the pump housing itself.

(I know it sounds rediculous but please humor me)

[NOMIEZVR4]

No problem, I'll do that today and report back. Battery is in the trunk too...

The car has no driveability issues BTW, drives great currently making 330whp at 11lbs boost

[IPD]

are you running the rails parallel or series (stock) feed? stupid question, i know, but worth asking.

[NOMIEZVR4]

Stock feed

[Greg E]

The issue is probably just FPR over run where you get very uneven pressure between the front/rear banks BUT in my experience, you can still get both O2s to cycle.

The last time I encountered this issue was on a customer car and the cause was a poor fuse connection with the fuel pump Hotwire. This is why I asked you to check the voltage at the pump.

[NOMIEZVR4]

The issue is probably just FPR over run where you get very uneven pressure between the front/rear banks BUT in my experience, you can still get both O2s to cycle.

The last time I encountered this issue was on a customer car and the cause was a poor fuse connection with the fuel pump Hotwire. This is why I asked you to check the voltage at the pump.

OK, just checked. 13.8 at the battery, 13.6 at the pump housing itself on a cold start. So then are we concluding the culprit is the FPR being overun? Shouldn't it be running rich and the trim settling at -12.5 though? Especially on the front bank, relatively speaking..

[Greg E]

Unless there's a serious flow mis-match with your injectors, No. There's a surge of fuel on the rear bank. The front gets trimmed after the rear. So essentially the rear bank is the "base" trim and the front is compensated off that.

I know it's confusing....

Try playing with increasing the values in the MAF Smoothing (VE) table from 100hz and lower. See if that brings that front O2 to life.

[NOMIEZVR4]

Unless there's a serious flow mis-match with your injectors, No. There's a surge of fuel on the rear bank. The front gets trimmed after the rear. So essentially the rear bank is the "base" trim and the front is compensated off that.

I know it's confusing....

Try playing with increasing the values in the MAF Smoothing (VE) table from 100hz and lower. See if that brings that front O2 to life.

Will do. I'll report back shortly.