LSXRX7

I have an LS6 that runs lean at WOT. Not sure if it is a sensor or internal. 90% of the time it runs lean at WOT and sometimes it runs fine lots of power seems to run its best on the freeway and like crap on the street from a stop…. Car runs fine up until about 4800 rpm lower RPM seems fine. Has MS3 cam, springs-pushrods, 90/90 42# injectors *new fuel line fuel filter, regulator, IAT sensor,TPS sensor.
It has been tuned as well (SD) but think it needs to go back cause I milled the heads a bit. But am stumped because it does run ok sometimes.. Anyone have any ideas please let me know thanks…

p.s. i dont have a wide band just a crappy narrow band thats how i know its running lean besides the fact that it feals like the anchor is getting thrown out at 4800 RPM

Frost

iTrader: (45)

Stop making pulls until you get it (re)tuned. If that NB based gauge says lean then it's leaner than 14.7 @ WOT, which is not where that you want to be.

LSXRX7

ok i was just wondering if there was a sensor that could cause this?`since it is on SD tune, maby the aftermarket 2 bar MAP, cam position sensor??? it only goes lean on the narrow band when the RPM's get around 4800. other than that it stays rich.

69LT1Bird

iTrader: (1)

What is your fuel pressure when this happens. Get a gauge and tape it to your windshield and watch your fuel pressure when it falls on its face.

98Camarod

iTrader: (43)

There are plenty of tables that can make it do that, get it tuned