frankgtb

my 2006 ls2 is bone stock track car and pitch black inside the exhaust tips indicating rich and maybe building up soot and carbon on the exhause valves

well running ferrari,bmw,audi etc etc produce tan/grey inside their exhaust tips

no check eng light, eng runs perfect

looked at all 4 o2s with my live data scan tool, all 4 looked busy measuring away busy

iam still running cats

both short term and longterm fuel trims were changing values quickly as well

what color is the inside of your corvette exhaust tips?

will leaning the mixture via hptuners/efi live produce same power, reliability yet cleaner exhaust ?"???

AU N EGL

Black That is normal

el es tu

hate to sound like captain obvious, but rather than just haphazardly changing the fuel, why dont you just get it tuned/tested on a dyno?

sabastian458

Black is normal on the inside of the tips.

AU N EGL

Then drive the chit out of her.

froggy47

Every stock one runs rich (black pipe).

Black89Z51

Factory fuel trims are rich to meet NOx (I believe) emission requirements, and for a safety margin.

RX-Ben

Not always the case - I had the opposite (very clean tips) on my stock C5.

steve J06

same car here, black color and very thin layer of soot inside the exhaust tips.

Dale1990

2006 LS7 here and my exhaust tips are usually black inside. From what I've seen, GM tunes these engines on the rich side for emissions and longevity - more fuel makes for a cooler combustion event.

VGLNTE1

what color do you want burned fuel to be?

frankgtb

tan/grey from what i know is a good combination of power and reliability

light grey/tan can indicate too lean

Black89Z51

How many of these other cars are you comparing to are also naturally aspirated?

Turbo exhaust temps. are significantly different and will effect exhaust color.

Check your plugs for a little more accuracy.