Manufacturer Control Fuel Air Metering Issue

Really need some help on this. I have a 2000 Mustang GT. This is my first hot rod, and I'm pulling out what little hair I have left. These are the new parts I have supplied to my GT:
Ignition coils ×8
Motorcraft platinum plugs ×8
Fuel Filter
TPS
Mass air flow meter
PCV valve
(And among other items.... Rack and pinion, shocks and struts, brakes, inner fenders, spoiler, ball joints, throwout bearing.)
I'm at my wits end and I've spent all the money I can on this car right now. Out of options, out of patience out of hair.
 
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Its throwing codes for all four O2 sensors and manufacturer controlled fuel air metering. Also throws an egr insufficient flow code from time to time, but there is a delete plate on it. I've also traced down my vacuum hoses and does not appear to have any leaks.
 
It would help us to help you IF the full DTC codes were posted.

If looking for a guess, have you checked all of the fuses? Especially the fuses responsible to power the O2 heaters F2.2 and F2.8.

Is it really a surprise that the PCM would throw a DTC code for no EGR flow when the EGR system has been blocked off?

On a modern car I don't really understand the gain from deleting the EGR system. EGR is disabled by default when the throttle is at WOT. So there isn't any additional HP to be gained by deleting the EGR system. Deleting EGR just adds "issues" when it's time to trouble shoot or get your car inspected.

If you don't mind me saying this, you don't sound like the kind of person that wants to chase HP at all costs. In this case, consider staying closer to "stock" trim.
 
It would help us to help you IF the full DTC codes were posted.

If looking for a guess, have you checked all of the fuses? Especially the fuses responsible to power the O2 heaters F2.2 and F2.8.

Is it really a surprise that the PCM would throw a DTC code for no EGR flow when the EGR system has been blocked off?

On a modern car I don't really understand the gain from deleting the EGR system. EGR is disabled by default when the throttle is at WOT. So there isn't any additional HP to be gained by deleting the EGR system. Deleting EGR just adds "issues" when it's time to trouble shoot or get your car inspected.

If you don't mind me saying this, you don't sound like the kind of person that wants to chase HP at all costs. In this case, consider staying closer to "stock" trim.

You are correct in saying I'm not chasing HP. It has plenty.....when it runs right. As far as fuses go...I should kick myself in the rear for making that nube mistake. Unfortunately, its not the fuses though. One person I talked to suggested I check my fuel pressure regulator because he said it sounded like its dumping fuel into the system when it shouldn't be. I'm thinking this is viable. Don't know why I haven't thought of that to begin with. Guess my brain was in retard mode from all this lol
 
Saw this too. Diodes spliced into wires...looks like they used to be tied together or to something else. Location is to left of the fuse panel in the left kick panel
 

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Not too concerned with the o2 Codes issue. Its dumping too much fuel. o2 codes were showing up when I got the car....it ran fine then. Only been over the past month it started running bad.
But to answer your question, it does not have cats. Downstream o2 sensors have been deleted.
 
Catted or not? If the X-pipe has no cats at least two of your codes (what are likely the cat efficiency codes) can be explained.

Turns out....the upstream o2 sensors were coated with soot. My guess is from the malfunctioning MAF and the fuel/air ratio being off. Took them out Friday and cleaned them, reinstalled and my GT hasn't had a hiccup since.
One of those duh moments. But I took the input that was given from you guys and applied it. It was a big help.
Thanks guys!
 
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