I have an SCT chip burned by a local tuner on my 03 L with 4# lower. The dyno was good at 381/474 with A/F @ 12.2, which is good at WOT. I think I am running too rich at cruising speeds though. The Bassani tips are black with soot and my gas mileage is terrible. I don't think my tuner made any attempt to adjust the fuel tables at anything other than WOT. I'm kinda new at this but I assume a tuner has that capability. I am thinking of buying a Predator for the truck. I understand that when you first attach the unit to your truck, it reads your stock tune and becomes "married" to that vehicle until you return it to it's original state. If I get the Predator, do I remove the chip first or do I leave it in place prior to the first time using the Predator? Would I be better served to just ditch the chip altogether and just have it tuned via the Predator? My future plans include either porting the blower or waiting for the Whipple to come online. Also, I just ordered a Dynojet Wideband and should be getting that in place next week so I'll be able tell more. Thanks in advance for the help.

 

Unless the maf transfer is off by a MILE the computer will bring the idle and cruise areas back to 14.6:1, so I doubt that's a problem. The only time it will go richer than that is under open loop which is wot or aggressive driving situations. The factory tune also runs at the same 14.6:1 in the same idle/cruise areas so the gas mileage difference shouldn't be there. Now reduced timing, or the maf being off by a ton would affect the mileage. Usually, the extra power has you driving a bit harder, which can change your mileage a LOT! With the milder mods most tuners don't touch the maf anywhere but open loop WOT (or nearly) areas.

By the way, todays unleaded will turn your tips black, even on 100% stock vehicles. Looks like it's real rich, but not true.

As far as switching to a Predator or other flasher, they'll have you re-install the stock tune back in the truck first to copy it, so the chip should be removed first and I'd remove the battery cable for 10-15 minutes also to clear any trims in the computer. Then load your flashed tune.

Jody

 

I've often wondered if having the excess oil in lower manifold problem that we have would cause soot on the tips...
That is if you don't have the PCV deleted or oil seperators..

 

I have deleted the PCV system and using breathers. As far as gas mileage goes, I'm getting 12.1 with almost no highway miles and staying out of boost. I thought that was kind of low, but I don't know what others are getting. I also think I remember him saying he turned off the 02 sensors and EGR. Timing is at 15*. Maybe everything is fine.