Even on the 92+ blocks there is still a place tapped in for the ect sensor with the two nipples all you have to do is just remove the plug. The stock d-series ect sensor is the same as the older ls and b16a1. Ive always just run the ect sensors like this and did the same on my lsvtec(92 ls block). Im not sure but the ect sensor in the t-stat housing might operate at different voltage readings and they might be upsetting the pr3 ecu that was programmed with the green two nipple type sensor. Not saying thats deffinitely the answer but just what has worked on lsvtecs for me.


edit: the d-series ect sensor I was refering to was 88-91.