I/m readiness test and cel reading

My grand marquis was running poorly and had a cel on so i
went and bought the noxwell nt201 to check it. It had 4
codes, tps, iac, egr and this p0430. I had shop change the
tps, iac, egr, maf and cleaned throttle body and egr ports. I
drove it after resetting it and only p0430 came back. Took it
back to shop and then they changed both o2 behind the
catalytic converters. Drove it home to get the same code?
So after spending 1800$ it still has something wrong. I
hooked up the scanner and used the i/m readiness and the
abbreviation mil had a light bulb, hcat had a red circle with
line through it, and the same with air had the circle with line
through it? Thank you for any insight or information