1997 f150 4.2l v6 rough idle,8mpg,throwing 6 codes
 

so i bought this truck about 3 months ago and it was running real bad when i got it, i went ahead and changed the lower and upper intake gaskets, cleaned throttle body, egr ports on lower and upper intake,did timing chain cover gaskets, and 3 bad injectors i found while doing gaskets, truck ran better but still black smoking(running rich) and getting 8 mpg.so i changed fan clutch,fuel pump fuel filter,airfilter,MAF sensor(old one was pulling 14.4 volt),DPFE sensor,andall 4 oxygen sensors(old ones carboned up and real sooty),ive checked my egr valve while idleing and when it opens the engine just about stalls, truck seems to be running better but CEL light came on again and is throwing these CODES: p0453(evap emission ctrl sys pressure sensor high input),p0141,p0153,p0135(oxy sensors),,p0401exhaust gas recirculationflow insuff detected,p0460fuel tank level indicator circuit error.and i believe ive told everything i know so if anyone out there can help me outor point me in the right direction i would greatly appreciate it.
thanks.

and changed spark plugs twice with motorcraft.

P0141 says the PCM has detected a short to ground, a short to power, or an open in the bank 1 sensor 2's heater circuit. (A short to ground could cause multiple sensors to not funtion correctly.)

P0153 says the PCM tested the frequency and output amplitude of the oxygen sensor bank 2 sensor 1 and found the response time below a specified limit. Do you have any exhaust leaks on bank 2 upstream of the forward O2 sensor?

P0135 says the PCM has detected a short to ground, a short to power, or an open in the bank 1 sensor 1's heater circuit.

Did you have to splice these new HO2S wires to the old connectors?

Also, double check that the vacuum hose is connected to the fuel pressure regulator, AND, that it has vacuum when the engine is running.

Thanks for replying and the new oxy"s sensors plugged right up and did not have to splice and do have a small pin hole exhaust leak on passenger side right before new catalytic converter, and I was checking IAC valve and manual said ohm out either iac terminal to the iac body and should have 10,000 ohms, I had no ohms between iac body and iac terminal does that mean its bad, I had 12.5 volts on iac plug harness side and 7.5 ohms between both iac terminals,

And the big vaccine house that goes from vaccum regulator to egr valve I "believe" almost is sucking closed.

Why would you spend all that money and effort just guessing?
It is never the way to go about the repairs to the engine control system.
The codes are built in for trouble shooting use by one who has some idea what they mean or they are useless if ignored.
You poor mileage is mainly from the OX sensor issue the PCM is setting codes for.
Sounds much like a harness problem.
Without the Ox sensors working, the computer falls back on 'rich' 'fixed' fuel tables to run the engine on.
You need to get this fixed first then go on to other codes and solve for them.
Otherwise you have too many issue all at the same time causing confusion.
Sorry to jump on your shoulder like this but you need to change the way you go about this.
Good luck.

Bluegrass knows his stuff and will lead you in the right direction.

To back up what he said, my recently purchased 4.2 was giving me 10mpg and replacing the old, original o2 sensors doubled my mileage. The o2 sensors have a big effect on mpgs if they aren't operating properly.

I had the trick in 2 different shops and one said fuel pump was bad and I checked fuel rail pressure after I changed gaskets and it was good and the other just told me to replace oxy sensors, so you believe harness isn't supplying proper power to new oxy sensors?

Both you and your shops are not looking at the code discriptions and not using them to tell what the issue is.
Look at the codes 135, 141, 153.
They are 'all' telling you the same thing for both sides.
Shorts to power!
Get under and look at the harrness for burns or rub-throughs against the exhaust or some other location.
Stop playing a game of questions and do the work.
A condition like this, they cannot provide the signals the PCM needs.
If there were shorts to ground the fuse #23 feeding them would blow and cause even more issues.
Sorry to be forceful but you have to go at this the correct way because you not getting it fixed the way it's been done so far or you would not be hear for help..
The bottom line is you should be able to take care of this yourself.
Good luck.

im here for help because im not mechanic, appreciate the help.

Respectfully, I sensed the same but needed to break the ice so you can make progress by appealing to your better sence.
That means you have to move past the position your at, in some way.
I explained why and what to do when I saw you were not getting enough direction..
Good luck with it.