Och

iTrader: (3)

Do you lose EGR?

JBrady

The GS4xx models that the S&S were designed for do not have EGR. On earlier models with EGR you can plumb from after the header outlet flange if EGR is desired. This can be done in downpipes for vehicles with cats relocated under the car or in the actual cat housing itself just like an O2 sensor bung install.

Och

iTrader: (3)

Oh cool, I didn't know GS430's didn't have EGR. Isn't it required by law?

JBrady

Lexus accomplishes EGR with the VVTi. It creates exhaust overlap and therefore exhaust gas recirculation under certain conditions. This actually makes the engine less smooth than previous models. My 1999 LS400 w/VVTi (no EGR) does not idle as smoothly as my previous 1996 LS400 w EGR.

Och

iTrader: (3)

Yeah but it gets rid of so much stuff on top of the engine, vacuum tubes etc. I can also attest that my 94LS idles much smoother than my 01 GS430, but then my GS430 has seen no loving in a little over 100k miles. In the next month or so, I'm giving it a major tune up, and hopefully it will smoothen the idle out.

GS FONZy

iTrader: (6)

My SC with high milage idles smoother than my low milage GS.