To clear codes for a retest, disconnect the jumper while the codes are dumping or disconnect the battery for 10 minutes. Clearing the codes does not fix them, it just erases them so you can retest and see if they come back.
Code 12 -Idle Air Bypass motor not controlling idle properly (generally idle too low) - IAB dirty or not working. Take it off and clean it thoroughly with throttle body cleaner. Clean the electrical contacts with non flammable brake parts cleaner at the same time.
Code 14 - Ignition pickup (PIP) was erratic – the hall effect sensor in the distributor is failing. Bad sensor, bad wiring, dirty contacts. You have to press the distributor gear off the shaft to replace the sensor. The pip signal is used for ignition timing and fuel injector timing.
Code 18 - SPOUT out or wiring fault - look for short to ground in SPOUT wiring going back to the computer. Possible bad TFI.
Code 33 - Insufficient EGR flow detected.
Look for vacuum leaks, cracked vacuum lines, failed EGR vacuum regulator. Check to see if you have 10” of vacuum at the EGR vacuum connection coming from the intake manifold. Look for electrical signal at the vacuum regulator solenoid valves located on the rear of the passenger side wheel well. Using a test light across the electrical connector, it should flicker as the electrical signal flickers. Remember that the computer does not source any power, but provides the ground necessary to complete the circuit. That means one side of the circuit will always be hot, and the other side will go to ground or below 1 volt as the computer switches on that circuit.
Check for resistance between the brown/lt green wire on the EGR sensor and pin 27 on the computer: you should have less than 1 ohm.
See the following website for some help from Tmoss (diagram designer) & Stang&2Birds (website host)
http://www.veryuseful.com/mustang/tech/engine/images/fuel-alt-links-ign-ac.gif
http://www.veryuseful.com/mustang/tech/engine/images/88-91eecPinout.gif
EGR test procedure courtesy of cjones
to check the EGR valve:
bring the engine to normal temp.
connect a vacuum pump to the EGR Valve
apply 5in vacuum to the valve.
if engine stumbled or died then EGR Valve and passage(there is a passageway through the heads and intake) are good.
if engine did NOT stumble or die then either the EGR Valve is bad and/or the passage is blocked.
if engine stumbled, connect vacuum gauge to the hose coming off of the EGR Valve
snap throttle to 2500 RPM (remember snap the throttle don't hold it there).
did the vacuum gauge show about 5in vacuum?
if not, check for manifold vacuum at the EGR vacuum valve.
if you have manifold vacuum then connect vacuum gauge to the EGR valve side of the vacuum valve and snap throttle to 2500 RPM.
should read about 5in vacuum
The operation of the EGR vacuum regulator can be checked by using a test light applied across the wiring connector. Jumper the computer into self test mode and turn the key on but do not start the engine. You will hear all the actuators (including the EVR vacuum regulator) cycle. Watch for the light to flicker: that means the computer has signaled the EGR vacuum regulator successfully.
Code 95 - the following test path is for 86-90 model Mustangs.
The 95 code is because at one time or another, the fuel pump relay hiccupped and didn't provide power the pump when the computer told it to run. Sometimes this is a one time thing, other times it is a no run or runs poorly condition.
To help troubleshoot the 95 code, follow this link for a wiring diagram
http://www.autozone.com/images/cds/gif/large/0900823d80167162.gif
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 driver’s 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. 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. If there is good voltage there & at the Pink/black wire, swap the relay.
Some Mass Air conversions neglect to run the extra fuel pump wire, and they always have a 95 code. See
http://www.stangnet.com/tech/maf/massairconversion.html for more information on the Mass Air wiring conversion.
The TFI module and pip faults are the top suspects for your problem. The TFI often fails when it gets hot and causes problems similar to yours. Remove the TFI module from the side of the distributor and have the auto parts store check it. Use a hair dryer to heat it since the problem only occurs when it is hot. Clean the TFI mount area good and use plenty of fresh heat sink compound on the TFI when you put it back on.
If the TFI checks out good, the pip is suspect. Seeing that you got a pip fault code, I would suspect it first. The pip is the sensor is in the bottom of the distributor that triggers the TFI. You have to press the gear off the distributor shaft to get access to it to replace it. Most guys just end up replacing the distributor with a reman unit for about $75 exchange.
