Sluggish Acceleration under load

[Coach Poffy]

I have a 2005 5.4L with 170,000 miles. engine replaced with rebuilt at 70,000 due to timing chain problems. Bank 1 cat replaced at 120,000. Now have very slow acceleration from stop and on highway around 1900-2000rpm. Checked datalog and O2 12 sensor was bouncing all around from .100-.700. Engine temp 190. O2 22 sensor was steady around .500-.600 with engine at 2000 rpm. Checked temp on cat 1 and input side was 390-410 output was about the same. Checked cat 2 and temp was 390 input/ 530 output. Figured cat 1 was bad. Replaced today at Midas. Vehicle still running with sluggish acceleration around 2000 rpm. Checked datalog again and get similar readings from O2 sensors. Did verify shop welded a cat on bank 1. O2 12 sensor still bouncing around between .100 -.500 amps at 2000rpm and engine temp 190-200. Cleaned MAS (not dirty) Checked Air filter. What do I look at next?

 

[Coach Poffy]

BTW there is no codes being thrown.

 

[01yellerCobra]

When was the last time it had a tune up?

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[HolidayJones]

I have a similar problem in my 2nd gen 03, with the old 2v. But mine is throwing lean codes. Acts like it's getting too much gas under take off

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[bedrck46]

what are the numbers on the codes

 

[HolidayJones]

I can't remember, it's been so long since I had to checked. My check engine light is just a permanent fixture at the moment

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