designo

iTrader: (6)

Yes the headers will fit. The flamges from the manifolds are 30 degrees further to the outside than on the ISF. Otherwise, the manifold pipes are identical to the ISF

However, once you decatt your primaries, you might ( and I use this mildly ) get a CEL that retards timing into failsafe mode, or just get a CEL without any retardation.

Rider

^ Both PPE and Sikky provide o2 conditioners making the car believe it still has cats.

Mesca

iTrader: (28)

Do iiittt Rider, be a pioneer! Would love to see some amazing results!

Rider

Just waiting for confirmation from PPE to start playing!

Jowett

You guys will see very nice gains with headers, little doubt about that.... a huge bottle neck on the GS460 1UR-FSE.

KevGS460ML

Do you actually have to remove the cats when going with headers? Im in TX so no cats = no inspection. Since the cats are huge bottlenecks i wonder if you gain anything significant by adding headers

Rider

^ my estimate would be a nice 20whp gain... IT did wonders on the ISF

Jowett

The ISF starts off with a much better tri Y header right from the factory, so do the 5.7 3UR equiped Tundra/Land Cruisers. They see awesome gains from both short and long tube headers.

Short tube headers can retain converters in the factory locations.

Rider

I may just test fit the stock ISF headers on my GS and take it from there.

dtd80

Definitely would be nice to have some performance increase on the 4.6. A shame no one has invested too much time on it for bolt ons.

Rider

LS460: http://lexus.sewellparts.com/oem-cat...S460-2009.html
ISF: http://is.sewellparts.com/oem-catalo...-ISF-2011.html
The headers look the same.. what do you guys think? Sewell has no replacement parts for the GS460!

Boron

If you looked deeper, you'd have seen the part numbers are identical.
Generally when that's the case, the parts are shared and therefore one and the same.

passnu2

iTrader: (33)

With the value of these dropping and bringing a whole new breed of owners now would be a good time for a vendor to have a set made up. Hope to see some more support for those that are looking to push the envelope

Rider

if you looked deeper, you'd have seen that the engines part numbers are identical too.. and last time I checked, they are not .. PNC is not the Part number.. the one under "details" is.

passnu2

iTrader: (33)

^ I still think you should push a vendor to get Sikky to make headers or anyone for that matter. I had a hard time getting anyone to do an exhaust or headers for us. Now should be a better time for someone to revisit this.