I was thinking about compiling a list of sludge prone vehicles. Here's the start of the list. Please feel free to add. And if possible cite your source so that this doesn't become a hearsay thread.
Camry 4 cyl. Produced 8/96 - 7/01
Camry 6 cyl. Produced 8/96 - 7/01
Solara 4 cyl. Produced 6/98 - 5/01
Solara 6 cyl. Produced 6/98 - 5/01
Sienna 6 cyl. Produced 7/97 - 5/01
Avalon 6 cyl. Produced 7/96 - 5/01
Celica 4 cyl. Produced 8/96 - 4/99
Highlander 6 cyl. Produced 11/00 - 7/01
http://yotarepair.com/Sludge_Zone.html
Camry 4 cyl. Produced 8/96 - 7/01
Camry 6 cyl. Produced 8/96 - 7/01
Solara 4 cyl. Produced 6/98 - 5/01
Solara 6 cyl. Produced 6/98 - 5/01
Sienna 6 cyl. Produced 7/97 - 5/01
Avalon 6 cyl. Produced 7/96 - 5/01
Celica 4 cyl. Produced 8/96 - 4/99
Highlander 6 cyl. Produced 11/00 - 7/01
http://yotarepair.com/Sludge_Zone.html