2000 Ford Mustang No engine light!

Okay I believe the fuel system is no longer an issue. And I did replace the fuel filter with a WIX brand and I was able to breath through that thing like it was just a straw. The FRAM, while brand new was highly restrictive. Very bad filters FRAM are. So moving on to another issue. I took off the vacuum hose for the brake booster and blew cigarette smoke into the hose in order to find a vacuum leak with the engine off. And to my surprise I found a vacuum leak coming out of the throttle body! Yet it was not coming out of the gasket area! It was coming out near the spring from the throttle shaft! Apparently Ford designed the throttle shaft with two O-Rings on either side of the throttle shaft that holds the butterfly valve. So now I am on the hunt for special O-Rings once again. Who knew that my throttle body was leaking internally and causing a vacuum leak! These O-Rings look like they are standard thickness, but they are a certain diameter. And the problem is that not even the Ford dealership produces my throttle body or the O-Rings that I need. So I was wondering if there was a way I could make this work? I was thinking about using a silicone sealant along with some O-Rings that I have. I have an assortment of rings, but the sizes available to me aren't quite right but they are real close. I am going to experiment with another size from the assortment. But, I was wondering if I could assist the seal with some sealant. I know that the throttle shaft has to rotate so I could not solely rely on sealant. So, do you think it would help to apply sealant around the O-Rings? A new aftermarket throttle body is very pricey for my car. I need to be creative here and fix this myself.

Hello I am back again, and I seem to have made some more progress. And the car is not completely fixed because progress takes money. Lol. But I did recently go to the junk yard and pull off a throttle body. And I performed the smoke test after installing it, along with a new paper gasket and it turned out to not be leaking through the throttle shaft like the original one was. The original one apparently had bad bushings in it, since I did find appropriate o-rings and it continued to leak. So, moving on to the last annoying issue that does not seem to want to go away. Firstly, I know that I have a charging system issue. This is because I have a Diagnostic Trouble Code coming from one of my lesser computers in my car, and not the Powertrain Control Module. My computer is complaining about low battery voltage, and the code will return normally within a week after I reset it. So there truly is an issue with my charging system. I have performed the parasitic drain test multiple times and the drain is within specifications based on the normal draw from my computers. So I know that no accessory is robbing any current when the car is off. The symptoms that I am having are, an extremely low idle while coming to a stop, and it's further troubled by turning sharply while parking. I know that if my car were an automatic I would be having a complete stall. The question here is. Is it the battery or the alternator? I can get either one brand new for the exact same price of 80 dollars. I know for a fact that the alternator does produce 14.5 volts at idle and the same voltage at every other RPM. My suspicions point to the battery. The battery will accept a 12.6 volt charge from the alternator after driving a while. But the battery will discharge to about 12.3 volts after only 48 hours of sitting with ideal weather outside. My other question is, can a bad battery cause my near stall symptoms? I heard that if the battery was less than par, that it would cause low voltage to get to my engine sensors (specifically my Throttle Position Sensor), and the ECU remembers the lowest voltage from my TPS and causes bad idle performance. I have also had the battery load tested they said it passed. Well I am wondering why the stupid battery refuses to hold a full charge no matter what, since I know that I do not have a parasitic drain. So, there must be other ways a battery can fail. I know the battery has experienced many full discharges which is considered 11.9 volts, and I believe this causes sulfation on the negative plates in the battery. I do not have any faith in this battery, but my question is, is it a known fact that a bad battery would be giving me my extremely low idle and performance issues? And is this due to the ECM being robbed of voltage and calculating based on random/intermittent readings of voltage? Thank you in advance.

Hello, I ended up just replacing my battery and I am able to see that this new battery does not rapidly discharge like the last one. There is not a test for the rate of discharge that is available to me. I know that the alternator puts out a really good voltage even with every electrical device turned on. So I no longer suspect the charging system.
And my car has a return-less fuel system and I believe the issue lies there. I have a Fuel Pump Driver Module that spins the fuel pump at an on demand rate, rather than a mechanical fuel pressure regulator and a fuel tank return line. I am almost certain that the FPDM is at fault here. In a previous message I remember saying that the junk FRAM fuel filter was restricted even when it was brand new, and I believe this overloaded my FPDM. I have performed a test on the FPDM and according to the instructions the module failed the test. The first step was to disconnect the FPDM. The second step was to turn the key on with the engine off. The third was to measure the voltage between two pins on the vehicle wiring harness. And it said if the voltage was greater than 10.5 volts, that I needed to replace the FPDM. The voltage that I measured was 12.5 volts! So the FPDM failed the test, but I guess what I measured was how much voltage the computer was supplying to the module when it is hooked up. If so, then if it is over 10.5 volts that means the module has hit its thermal limit one too many times. I suppose that restricted fuel filter demanded way too much from the module. What do you think about this testing procedure for the module? Does it make sense? What blows my mind is, how are you testing the module with it disconnected from the vehicle? I think I understand that its a reading that represents the demand and function of the FPDM under typical operation. Am I correct?

Hello, I will simplify my vast explanation of the testing procedure for the module. My reading was over 10.5 volts, I measured 12.5 volts. I replaced the module today though. I did disconnect the battery terminals while installing the module. Therefore, results are yet to be seen. I can tell a small difference already. It sounds deeper, and it runs a little smoother, yet the idle is not right as of now due to the battery disconnect. But, can you see why I replaced the module? It is crazy how the function of the module is determined with it removed from the vehicle, but I understand that it is a representation of the status of the module. I will post an update on the drive-ability of my car once it has been driven enough.