Dumped the codes tonight... need help

I had the same codes, i got the 96 because i jumped the fuel pump to turn on while pulling the codes, if you used a computer type thing to pull the codes, that might be why, i dont know i just use a paperclip to pull my codes.
Anyways, like i said i ahd the same 40 series and 90 series codes as you and i JUST changed my 02 sensors tonite and it made a world of difference. It fixed my fluctuating idle, and it smelled "cleaner" when it was idling. I took it for a drive and believe it or not it felt a little better. Definite better throttle response. I would change the 02 sensors, they are only like 85 for both at autozone or advance.
When you disconnect the o2 harnesses, i recommend spraying some electronics cleaner in the old harness on the car. Mine were all crappy inside.
Also, if your going to buy an 02 sensor removal tool, DONT buy the 7/8ths size. Make sure you get the metric one. I bought the 7/8ths size and it almost ruined my day. I ended up having to break the old o2 sensors and using a (21mm socket i think) to remove them. Putting the new ones in i just used the 7/8ths tool and didnt wrench on them real tight.
anyways, just my 52 cents.
Good luck.

Code 96 – KOEO- Fuel pump monitor circuit shows no power - Fuel pump relay or battery power feed was open - Power / Fuel Pump Circuits.

Look for a failing fuel pump relay, bad connections or broken wiring. The fuel pump relay is under the passenger seat. On Mass Air Conversions, the signal lead that tells the computer that the fuel pump has power may not have been wired correctly. See http://www.stangnet.com/tech/maf/massairconversion.html

To help troubleshoot the 96 code , follow this link for a wiring diagram for 86-90 models http://www.veryuseful.com/mustang/tech/engine/images/fuel-alt-links-ign-ac.gif

Look for power at the fuel pump - the fuel pump has a connector at the rear of the car with a pink/black wire and a black wire that goes to the fuel pump. The pink/black wire should be hot when the test connector is jumpered to the test position. . To trick the fuel pump into running, find the ECC test connector and jump the connector in the lower RH corner to ground. http://www.mustangworks.com/articles/electronics/eec-iv_codes.html for a description of the test connector. it. No voltage when jumpered, check the fuel pump relay and fuse links.

86-90 Models:
Using the diagram, check the red/black wire from the fuel pump relay: you should see 12 volts or so. If not, check the inertia switch: on a hatch it is on the drivers side by the taillight. Look for a black rubber plug that pops out: if you don't find it, then loosen up the plastic trim. Check for voltage on both sides of the switch. If there is voltage on both sides, then check the Pink/black wire on the fuel pump relay: it is the power feed to the fuel pump. Good voltage there, then the fuel pump is the likely culprit since it is getting power. No voltage there, check the Orange/Lt blue wire, it is the power feed to the fuel pump relay & has a fuse link in it. Good voltage there & at the Pink/black wire, swap the relay.

You unplugged your fuel pump relay.
The inertia switch is in the hatch area back by the tail lights. If you got code 96 in the second round of codes or continous/memory round, it was because you had the fuel pump relay disconnected earlier while you had the key turned on when you changed your fuel filter.

Do you O2 sensors and clear the computer of codes and you should be good to go.

Mario

86T-Top said:

You unplugged your fuel pump relay.
The inertia switch is in the hatch area back by the tail lights. If you got code 96 in the second round of codes or continous/memory round, it was because you had the fuel pump relay disconnected earlier while you had the key turned on when you changed your fuel filter.

Do you O2 sensors and clear the computer of codes and you should be good to go.

Mario

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Good catch!

While pulling the codes during the KOEO test, disconnect the jumper cable you used to pull the codes. Then disconnect the battery for about 10 minutes. These town steps will clear the codes for you.

Mario

wtf are codes? does this have to do with the maf and all the sensors? what if i dont have the big mas airflow thing on my cai will my car run? i also see these two connections towards the back of my engine what are they. and there are the things on my h-pipe that are threaded wehat are they for?

pconway said:

wtf are codes? does this have to do with the maf and all the sensors? what if i dont have the big mas airflow thing on my cai will my car run? i also see these two connections towards the back of my engine what are they. and there are the things on my h-pipe that are threaded wehat are they for?

Click to expand...

a repair manual is a beautiful thing. I have no idea what you are talking about, but i will try.

the computerized engine management system has parameters and the ability to do self diagnostics. when something is not within parameters, a code can be stored. then we retrieve the codes.

the connectors at the back of the motor might be the 10 pins (giving a description might have helped us help you).

the things in the H-pipe are oxygen sensors.

cjman15 said:

Got my o2 sensors, but I just went out to tha garage and I don't think I have a 21mm wrench... haha sh itty will it work w/ an adjustable or you think it'll be too tight

Click to expand...

It will probably be too tight for the adjustable wrench, but give it a try.

Mario

HISSIN50 said:

a repair manual is a beautiful thing. I have no idea what you are talking about, but i will try.

the computerized engine management system has parameters and the ability to do self diagnostics. when something is not within parameters, a code can be stored. then we retrieve the codes.

the connectors at the back of the motor might be the 10 pins (giving a description might have helped us help you).

the things in the H-pipe are oxygen sensors.

Click to expand...

there is a wire with a connection i see in ppls cars that connect to comething that is on the the cold air intake. isk what it is. do i need it for my car to run? and do i need the 02 sensors? will i pass emissions?