2005 Ford 3.0 Vulcan runs lean after cats hollowed out.

2005 Ford Taurus 3.0 Vulcan

Everything is factory.

Cats hollowed out because they were plugged.

Verified by removing them and looking inside, too expensive to replace.

Reinstalled after removing honeycomb.

Car throws a lean condition code.

Are the factory injectors able to be tuned? Need bigger injectors? Need an aftermarket MAF sensor? All of thee above? Any thoughts/suggestions on the matter would be awesome.

(Car is obviously not used for on road purposes for the sake of this forum)

Due to the back pressure, then long-term trim may have leaned out the mixture in the OEM ECU. Now it flows better and is running lean until it re-learns. You might try disconnecting the ECU from power for 5 or 10 minutes, then re-connect -- it may start re-learning.

Or it could be that either your 02 sensors (fouled from excess mixture while cat was plugged) or injectors (clogged and can't flow what's needed now) need to be replaced.

Make sure you don't have a leak in your exhaust system since you removed part of it to inspect the cat. exhaust leaks can draw in extra oxygen in low RPM situations.

Appreciate your thoughts on the matter.

O2's are brand new.

No leaks in exhaust.

New exhaust gaskets were used.

Made baffle plate with ever so slightly smaller radius than intake pipe size to restrict air flow.

Works awesome, car idles better and does not throw a lean code no matter the driving condition with baffle plate installed.

MAF Sensor voltage out of spec when watching with scan tool. Ex. 1.06 volts at idle, Should be .8 volts. Approximately same numbers with or without baffle plate.

At higher rpms, highway speeds, without baffle plate, car runs awesome 02s read as they should.

Let car come back to idle, 02s show lean numbers, and car idles rough without baffle plate.

Possibly still fuel injectors?

Baffle plates where?

Yeah, that baffles me, too...

Obviously, in the baffles...

Baffle plate is installed in the air filter box.

Installed after the air filter and before the MAF sensor.

Why? There's no logical reason for that and it's counter to improving efficiency, torque, and power?