Knocking when it shouldn't

**Reptile** · 12-30-2015

Fuel trims should lock in at zero. What are the LTFT's at idle and cruise? Do you still have your stock PCM, or did you send it back to ZZP?

**Dadkota** · 12-31-2015

Idle LT is -0.7 and cruise LT is -2.3 if I remember correctly, I would need to look again though. But yes I sent the stock unit to ZZP, wasn't thinking I would have a problem you know?

**SgtMarshal** · 12-31-2015

I liked my tune done by Overkill. Wires won't make any difference, except that they look cool. a bigger throttle body with a bigger mass air flow sensor, like the combination I have for sale in the classifieds, will increase the volumetric efficiency of the engine resulting in more power.

**Dadkota** · 12-31-2015

My mistake, cruising LT is 0.0-0.7

**Fivefingerdeathpunch** · 12-31-2015

Within 3-5% of zero is just fine.

**Dadkota** · 12-31-2015

So an in-car tune it is to kill this KR? Any other things you can think of?

**Reptile** · 12-31-2015

Weird, if the LTFT is that close, the trims should lock in at zero in PE.

**Dadkota** · 12-31-2015

What is PE?

**Scottydoggs** · 12-31-2015

PE= power enrichment. your car goes into pe mode when ever the gas pedal is 40% throttle or more on most set ups.

**Dadkota** · 12-31-2015

Jesus i have a lot to learn lmao it usually doesn't snap to 0.0 but something like 1.5 or so during these instances

**Scottydoggs** · 12-31-2015

when you do go wot the ltft should lock in at 0.0 but -5 to +5 is considered safe. closer to o.o the better.

**Reptile** · 12-31-2015

The trims shouldn't be +/- 5 at WOT...there's a problem there if they do.
Fluctuating at idle and cruise at +/- 5 is what's acceptable.

**Dadkota** · 12-31-2015

It snaps to 1.5 at WOT, no fluctuations.

**Fivefingerdeathpunch** · 12-31-2015

Watch the wideband is what I always do.

To me it does not matter if they are within 3-5% of zero and the wideband says I'm good on fuel. No way that that small percentage is going to matter really.

The stock maf calibration on my 2012 silverado with stock airbox is within 2% of zero all the time and it doesnt change a thing.