I am pretty sure my pyro guage is toast. I have a isspro EV1 style. I just replaced the amp box and it did not help. The issue is when i am driving it takes a long time to show temp readings, then for ex after running at 80 mph on the freeway, then coming down the the end of the ramp it will drop down to the 100 or bottom of the guage. I am sure it should at least be like 500 if i remember. So I figure ill replace it with a EV2 ( no more ampbox) and a new thermocouple. questions is the old thermocouple has been in there since about 2007 and looks pretty rusted up to the manifold. Has anyone tried to replace it and will it snap off? I was going to pb blast it for a few days first.
thanks For your help. Jeff

 

my sensor was in a Stainless steel compression fitting and came off easy, it might just be rust on tope of it. PB blaster on it for a few days cant hurt if it don't come off easy

 

I had to change mine when my gauge went bad and it came right out. I don't recall how bad it looked.

 

I just had a 8 month old EV2 pyro gauge go bad. It would not light up, sweep to max/min when turned on and was stuck at 350 or so. Called ISSPro and they sent a new gauge out at no cost to me and I sent the old one back. The tech said they see about 1 of those a year, so I guess I was the lucky one.