I have a 98 LS400 with, what may be the same problem. My version is this. When approaching a stop, but before the car comes to a a complete stop, moving my foot from the brake to the accelerator, the car appears to slip in to neutral. That is, pressing the accelerator produces no acceleration. The engine either races or idles (I can't be sure) but the car does not respond. This hesitation or stalling lasts for 1 or 2 seconds, then something "engages" causing the car to leap forward. When I first reported this problem to Nalley Lexus, here in Atlanta, I was told this was a common problem and replacement of a "ECM" might fix it. Although the dealer expressed a hesitancy to replace the $1100.00 part. When I insisted, I was told that if the new ECM didn't fix the problem, there was nothing else the dealer could (or was willing to) do. The replacement ECM improved the hestitation enough that I was able to live with the symptoms.
Now, a good friend of mine has recently bought a 99 LS400 (on my recommendation) from the same dealer. He has the same problem but much worse. When he called Nalley Lexus, he was told to not even bring the car in because there was nothing they could do. Thinks about it. A $60,000 car and the dealer says: "Tough sh*t". Any suggestions?
