Help 99 Escort ZX2 2.0L DOHC upper O2 sensor

I am in the process of changing the upper oxygen sensor. I manage to get the old one out but am having a hard time installing the new one. I am wondering what the trick is. The area is so hard to get at and I have so far been unable to get the thing to start treading in

There is no trick...
Are you turning the right way?
Are you sure you have the right replacement part? Compare the threads on the new and old one.

Finally got it
Put a bit of oil on the treads and it screwed in ok.

for mine, the orig O2 was shorter than the aftermarket

original heated O2 on engine was removed with an O2 sensor deep well socket, but no go on replacement

for replacement, try hand threading new into hole until you get it hand tight, then crowsfoot on extension to get it tightened down... there's a torque spec you should follow for this-- i'd recomment a torque wrench for this part to keep from overtightening

best luck

hope my struggles with mine help you

(my escort's problem turned out to be pcv hose elbow by firewall-- after changing out oodles of other parts first :) )