o2 sensor isolator ever debunked?
 

so did we basically decide that using one of those was dangerous for your engine? and did they actually save fuel?

Did you mean insulator or extender?

One trick is to wrap the O2 sensor, another is to put an adapter ring in to pull it out of the exhaust stream a tad.

yeah I'm thinking of the adapter to pull it out of the exhaust a tad.

I tried the adaptor on my '88 Escort. It didn't help FE and when I removed the adaptor the 02 sensor was black with soot as though it had been running rich.