botbullet0

I just bought an LS400 that has a GS400 specific Weapon R Secret weapon cold air intake. It also has a custom cat back exhaust with two borla mufflers. I'm pretty sure that the O2 sensor locations haven't been changed. It's throwing a rich bank one code which I assume is because of the intake. The previous owner included an Apexi Neo, but I'm not sure I really want to go that route. This is my daily and I want reliability over power.

I heard the K&N intake doesn't require any ECU rework. I've been looking for stock air cleaners but it's been pretty hard to track down a full setup. Would the K&N get rid of the rich issue or will I have to go back to stock?

firelizard

iTrader: (1)

Not much difference between all the aftermarket intakes, they are pretty much all just an L shaped tube with a cone filter.

botbullet0

Right, but I read that the Weapon R needs a piggyback for Air Fuel because the diameter is different than stock. That causes a bad MAF reading. Supposedly the K&N doesn't cause this issue. Anyone familiar with this?

SoCal Cyco

iTrader: (20)

wanna sell/give me the neo?

badblackgs

iTrader: (1)

I'd like to chime in on this party. I have first hand experience with how the smallest decrease or increase in intake pipe diameter changes the air fuel ratio. can you take the time to measure the inside diameter of your intake pipe where the maf sensor is actually located? I know for a fact the factory diameter of the on a gs430 is 3 inches diameter. when I made my own custom intake pipe for my supercharger setup, the intake pipe was 3 inches outer diameter but 2.89 inner diameter. which caused my fuel trims to read rich at -12 on average. and when it went wot my air fuel ratio read 11.1 instead of the 12.5 it read when I had the factory air box set up in it. these reading taking from a wideband oxygen sensor. im familiar with the weapon r intake and never saw anything about needing to skew the maf signal. good luck.