new owner, check engine light woes p0125

[h0yitsdom]

just bought a 96 corolla with 127k miles
owner told me no check engine lights
started driving on the freeway today and the dreaded light turned on
guy i bought the car off of is a car flipper i guess and no answers/txt back so looks like im stuck with it lol

the engine code is p0125
when i checked it out with my reader it says some coolant problems, but checked online and it seems like the upstream o2 sensor is the real problem??

here are some pictures from what looks like someone already tried to repair or put in a new one but did a really bad job on wiring


heres some picture that i took of the o2 sensor, can anyone tell if this is a 1.6l or 1.8l as well lol

the blue tape is covering the plug

[speedy25]

The O2 sensors put out a millivolt output so its important to have a good connection AND shielding.

Small wire nuts will do in a pinch if you have messed up the stock connectors.

-SP

[h0yitsdom]

do you happen to know which color is which? i think my electrical connector was the problem
part number 90980-11030. i looked at it again today once i got off and am going to take a trip to the dealership tomorrow and see if i can get a new one and hopefully that will fix it

[trife96]

Ine way u can tell on the engine is look to see if it has a knock sensor screwed into the block or look at the oil pan. Is the oil pan one piece or two piece? If yes or yes then it's a 1.8. If not, it's a 1.6

It should be that knock sensor with the tape job, sorry I'm not good with electrical as much and I can't easily look on mine cause it's different now. But that's an easy fix bro

[trife96]

one way u can tell on the engine is look to see if it has a knock sensor screwed into the block or look at the oil pan. Is the oil pan one piece or two piece? If yes or yes then it's a 1.8. If not, it's a 1.6

It should be that knock sensor with the tape job, sorry I'm not good with electrical as much and I can't easily look on mine cause it's different now. But that's an easy fix bro

[Kiwi-Corolla]

Originally Posted by h0yitsdom

can anyone tell if this is a 1.6l or 1.8l as well lol

You can check to see which engine you have by looking at the number stamped vertically into the block, just to the right of the exhaust manifold. If you can't see it, give it a wipe with a cloth and use a torch to see what it says. If you've got the 1.6L 4A-FE it will say 4A and if you've got the 1.8L 7A-FE it will say 7A.

Here's an example of mine (it says 5A as mine is a 5A-FE) -

[speedy25]

Originally Posted by h0yitsdom

do you happen to know which color is which? i think my electrical connector was the problem
part number 90980-11030. i looked at it again today once i got off and am going to take a trip to the dealership tomorrow and see if i can get a new one and hopefully that will fix it

Color??

Typically dealers dont have or cant get connectors, but they are usually easy to find at the junkyard.

-SP

[h0yitsdom]

its grey, i went to a junkyard today and the guys lied so it was a waste of a trip, on the phone they said they had the connector and could cut it, when i get there they didn't even have any corollas. i ordered a new one from a website for $15, going to try to solder the old one back together and hope for the best

[h0yitsdom]

7A-FE engine i figured it was that since I have all powered windows locks and mirrors, but theres no badge on the back which threw me off

I was looking at the VIN plate but today i scrapped off some grime next to it and saw the engine code

[h0yitsdom]

i guess the main thing that I need now is the correct wiring order on to this plug for the damn oxygen sensor!

there are 2 wires, one is black and the other is brown i believe, i just need to know which goes where :\ or if someone has a picture of the plug still hooked up that would be perfect