All O₂ Heater + Purge Valve Codes at Once (P0135, P0141, P0155, P0161, P0443) — Fuse/Wiring Issue?

[Littleseavers]

Year/Model: 2005 Mustang GT (4.6 3V)
Mods: Steeda CAI, BBK throttle body, Borla ATAK exhaust, high-flow cats, Lito tune, misc suspension upgrades
Problem:
A few weeks ago, I suddenly got P0135, P0141, P0155, P0161 (all 4 O₂ heater circuits) and P0443 (purge valve) at the same time. My A/C also started acting weird it sometimes blows hot randomly, which seems tied to the same circuit.

What I've tried so far:

Checked and reseated fuse 45 already
Inspected visible wiring for damage (nothing obvious)Flashed back to stock tune briefly to rule out tune issues (car ran weird due to mods, but codes behaved similarly)
Symptoms is:

• Car runs noticeably richer with check engine light
• weird idle / A/C behavior changes
• No obvious misfires, but slight stumble at times and hesitation at launch

Has anyone dealt with this exact combo of codes before? It seems like a shared power feed or loose fusebox terminal. I'd love to hear from anyone who's had a similar issue or knows common failure points on the '05 GT for this circuit.

 

[waldo25]

I’m having the same issue. I’ve recently started getting backfires too, to the point where I gotta pull over and wait it out for a few minutes.