ECU for a 7afe in a 5sfe 1996 manual celica Options

[thebestofall007]

Hello all, I found a surprise in my 1996 Celica: It has an ECU for a 7afe manual transmission engine, however, mine is a 5sfe manual. The engine runs well, but gas mileage is not as good as it is supposed to despite replacing the cap, rotor, plugs, wires, and I get a P0141 code despite replacing the O2 sensor with an OEM Denso and checking the wiring connection between the sensor and the computer. The cables don't appear to be all spliced up, either.

Why would someone do this, and what would I have to do to replace it with the original (if this would fix the gas mileage and sensor issues)?

This post has been edited by thebestofall007: Oct 21, 2016 - 5:00 PM

[mkernz22]

I agree, get us some pictures so we know what we're working with

[thebestofall007]

I agree, get us some pictures so we know what we're working with

You asked, and here they are (Sorry I had to use imgur):

The engine:

http://imgur.com/a/t7Bv5

The ECU from the top (I did a search on the ECU's black numbers, and it came out of a '97. Does anyone recognize the numbers written in blue?):

http://imgur.com/MqoLsrh

The bottom of the ECU (Does anyone recognize the yellow numbers?):

http://imgur.com/6OMr2xL

The guts from the top (does anyone recognize if the internals are original?):

http://imgur.com/a/DNRDs

The guts from the bottom (does anyone recognize if the internals are original?):

http://imgur.com/eOtTTBG

And the plug:

http://imgur.com/WVU2THA

This post has been edited by thebestofall007: Oct 26, 2016 - 8:39 AM