Where is the map sensor

[Emerica19118]

i found a plug on the back of my motor that looks like its supposed to have something plugged into it.....its right inbetween the o2 sensor wires

 

[RALLIART15]

Sorry to bring up a dead thread but in the same boat.
I have a 93 4.0 Ranger, 183,x.. miles.
List of new parts between me and last owner,
MAF, TPS, O2, FILTERS
KOEO
172 right rich
173 right lean
176 left rich
177 left lean
KOER
411 idle high
412 idle low
Fuel pressure tested ok KOEO & KOER (don't remember exact numbers but was towards the low side)
Now for the confusing part, truck is in Sacramento elevation 35' runs like crap, surges, rough idle, 10mpg, garbage garbage garbage.
Went to OR last weekend elevation 3500' ran amazing, minimal surge barely noticeable, 16.9mpg thru 2 tanks full to empty, first tank took 16, second took 14.5 so I used most the tank..

SO... if anyone has any ideas please I am all ears....

 

[RALLIART15]

forgot plugs, wires, coil, and probably more..

 

[MrShorty]

How did it get from CA to OR: drove itself or towed? If you drove it up there, when did it start to drive well? Has it gone back to driving poorly?

 

[RALLIART15]

How did it get from CA to OR: drove itself or towed? If you drove it up there, when did it start to drive well? Has it gone back to driving poorly?

Bought it here in Sac, drove it to OR for a week at my parents, starting getting good as I climbed Shasta Northbound and ran great from there on North. On the way back it ran great from Redmond, OR to south side of shasta. First tank thru it was 16+mpg then after shasta next half tank was 13 then last tank into sacramento was 10.. seems the redding shasta area is where it went bad to good and back.

 

[RALLIART15]

Drives like dogshit again, no smoke but rich enough my bumper and bed are black..