Okay folks need abit of assistance please, my first ranger here 97 2.3 lima, always had problems im on the verge of workin out hopefully...
I changed all wires, all 8 plugs, idle air control valve, had both packs tested all came back positive, no vacuum leaks that i can find, both upper and downstream o2 sensors brand new, and have checked all wireing to and from on all sensors all checks out fine. Cleared any codes its might have had. Took for a test drive 10 mls ran fantastic, halfway back started to stutter pretty hard, limped home rechecked codes got these and doubles checked em on this sites code list.

po118 ect
po135 bank 1 sensor 1 upper failer
po141 down stream failer

both o2s are brand new and worked till it thru those 3 codes, now i should mention this was like 2 weeks ago when temps are in the 20s, would the ect make its fuel mix so off that it would "fail" the o2s readings? My temp gauge reads acurate so i never thought to change ect. As far as i know its this one...

and if i remember that is located just behind intake hose of thermostat housing on front of head at the top.