1996 F150 P0172 and P0175

Hello first time using a forum because this time im desperate!

Ok here is the thing, I have a 96 F150 v8 5.0 getting P0172 and P0175 which means rich condition both banks.

I have replaced the following:
Fuel pressure regulator
Cleaned MAF
Oil change and sparks
coolant sensor
192 thermostat
Checked TPS and is working properly

Using a scanner at idle I see something weird all STFT bank 1 are oscilating -0.78% to +1.78% STFT bank2 are little off -5.08 to 2.04% BUT LTFT on both banks stay at -25% if I press the pedal they go to -14% or -7% or so. while truck running numbers change a little but as soon as I stop LTFT go back again to -25% on every component change I do a KAM reset to make sure truck relearn values.
I did a vaccum leak test to see if values change and yes all values go to positive.
I also notice engine load at idle is around 42% if pedal press it goes up
what could it be?
MAF??

Need more info.

Map, MAF, Baro, Rpm, STFT, LTFT, ECT, TPS, O2s, Calc load

When did the problem begin? Any kind of work done recently?

What I do know is that it’s taking away a lot of fuel. Other PIDS will help aide the diagnosis but first thought is over-reporting MAF.

ECU uses MAF, MAP, Baro, and ECT to determine calc load

please take a look to attached picture

Time to check fuel pressure, IMO. I see that you've replaced the regulator, but that doesn't mean you have the correct rail pressure.

I will do that, I havent yet because as I mention before STFT look good but LTFT is always -25% and engine load around 42% at idle

What are your trims and engine load values with the MAF unplugged

Have you checked purge valve ?

will do today, actually yesterday night saw one of your videos where you are checking a ford explorer for a MAF problem. will update later, thanks!

yes, purge valve is working correctly.

Hi ScannerDanner
please see the pictures with my maf disconnected.
engine off disconnect maf then start engine stft values were way negative and after 3 or 4 min tried to go back to 0
Hope this screenshots be good reference for you

Among the other requests, let's just make sure you don't have a breathing issue. The scanner you have should provide PIDS for BARO( in in.hg) and ABSolute Intake Manifold pressure(in.hg).

Bring the engine to WOT (under load), you can try snap tests too. The ABS Intake MAN Pressure should rise within 2 in.hg of the constant BARO.

For example if the BARO is 29.2 in.hg, at WOT you want to see no less than 27.2 in.hg. In other words at WOT you want the intake manifold to go to atmospheric pressure. Anything less than 27.2 and you have an air restriction, Hence a possible reason for the higher calc. load.

Paul

my truck doesnt use MAP, it is a 96 ford f150 5.0 engine, it only uses MAF.

and yes my scanner reads baro but not in this truck

Hi renegadiel/guys,

Have you checked O2 sensor activity?

I had one which O2 sensor was always oscillating above 0.7 volts.

actually forgot to mention that I replaced them.
today I removed brake booster to make a vacuum and stft and ltft were positive. at the end a failure on system feedback message appear, and as soon as I put the hose back trim values went negative again around -20

Hi ScannerDanner
any recomendation after unplugg the MAF? I attached the pictures