dicer

I made an interesting discovery, while looking at some ad's for SC400's the 1UZFE engines in them have the stepper motor controlled EGR's, and the 92 LS400's still have the vacuum controlled EGR. Just wondering why? The LS didn't get the motor controlled egr till 93. Is it because they wanted to keep the LS platform standard from the previous years?

CELSI0R

Since Toyota was working on many revisions for 1993, I believe it didn't make sense to take the new features being put into the 1993 ECUs, and put in a few of the changes into the current LS (1990-1992), which still had many older electronic related components (ABS, TRAC, gauge cluster, etc) that would have needed to be updated or altered [not cost-effective if they can just wait a few more months and release them all at once instead].

Toyota also probably wanted to make sure the revisions to the LS were perfect before release, and they were not able to accomplish this by early 1992.