91 d21 Hardbody. 3-2. EGR temp sensor ohm specs?

150k miles, 1991 nissan hardbody pickup d21 ( 4 cylinder ) Applying vacuum to the egr at idle makes the engine bogg horribly but not stall. Cylinder balance test while egr is activated at idle; all cylinders react equally. BPT valve is working. Cold, the egr temp sensor ohms at 1mega ohm. With egr activated at idle for about 2 minutes the ohm spec is about 40k. Is this within specification? I am suspecting the egr is actually working but possibly the monitor system is faulty, ie; biased egr temp sensor. Any help would be appreciated. Thanks in advance.