95 Lumina service engine soon no code

Service engine soon light comes on just about any time I drive it till it gets warm. It is an intermittant thing, but it stores no code. It's been checked by two different code readers. Also, it seems to get a bit hot (not into the red) but hotter than it used to get.

A lot of code readers are junk. You need a scan tool reading with the engine data.
The ECM is known to go bad on the 95 model so get it read with a Scan tool

I forgot to mention, we have replaced the ecm and one sensor.