temp guage problems

[maxwax]

Ok my temp guage starts off working , and then when you hit the throttle it falls down past 100. if you let the car idle, it warms up and the temp guage works, but as soon as you mash the throttle it drops. the only changes that have ben made are, hp tuners programing ,turn fans on at 190 instead of 230, fans off at 195. cooler stat, and the rear o2's shut off. for 2 weeks no problems at all, and today I had the converters removed and both head pipes replaced, at this time I removed the down stream o2's all together, and on the way home I noticed the temp guage not working , so I pick up a new sending unit and install it and yet same story, do I need to plug the o2's back up and tie them up,or weld in new bungs and re install them, I dont know if they have anything to do with the temp guage or not( complete a circuit or somthing )


Oh, while any welding was being done I dis connected the bat.

[2001NBMZ28]

I'd try letting the car warm up and idle, then have someone watch the gauge while you move the ECT wires. Maybe it's the connector?