p0172 p0175

[Zackie]

Recently I bought a 2002 Sport trac to replace my 01 Sporty, I've had it for about a month now and suddenly it started running like absolute poop and is now throwing p0172 and p0174 codes, I put a new maf sensor on it and it has new fuel injectors (62 PSI from the rail) and I was wondering since I noticed, The thing just after starting not even a minute later the cats start to glow a bit, Could these codes be thrown by clogged cats?

 

[donalds]

Lets ask @410Fortune
Lean codes plus glowing cats

 

[Zackie]

Lets ask @410Fortune
Lean codes plus glowing cats

A good note I should add is its going back and forth weirdly from lean codes to rich codes on both banks

 

[410Fortune]

Is that a 171 or 172?

172 is too rich bank 1

174 is too lean bank 2

Houston we have a problem

Glowing cats are usually from too much fuel being ingested by converter,
Like an injector is just dumping it (stuck open)

Of course we clear the codes and then see how long before they come back, from what you describe it sounds like they come back immediately

First thing I would do is check fuel pressure in you said 62 psi at rail so that is in spec

Next is a full physical inspection of the oxygen sensors and their wiring make sure something did not melt
Check all around intake, exhaust engine with good brite flashlight check all wiring fuses hoses etc

Next is smell your oil, does it smell like raw fuel?

If everything checks out then I would be removing my intake plenum so I could get in there and inspect all air ducking and plumbing to and from including the fuel rail


Something went south
I suspect a stuck open injector or two on the rich side, bank 1 passenger bank.
Rich code means the 02 sensor on passenger bank has detected too much fuel in the air and has tried to compensate by adding less from the injectors, when it is in able to compensate and the rich condition continues you get a code.
Glowing converter only supports this condition. Now why the other bank would read lean, I’m not 100% sure but it could be because of too much fuel on the other bank and the computer has pulled fuel from the injectors, bank 2 may still be working,
Meaning the de fueling effort by the pcm on bank 2 worked.

Your converter may also now be plugged

But first let’s start with visual inspection and removing the intake plenum having a close look see at all hoses wires and gaskets

 

[Zackie]

Is that a 171 or 172?

172 is too rich bank 1

174 is too lean bank 2

Houston we have a problem

Glowing cats are usually from too much fuel being ingested by converter,
Like an injector is just dumping it (stuck open)

Of course we clear the codes and then see how long before they come back, from what you describe it sounds like they come back immediately

First thing I would do is check fuel pressure in you said 62 psi at rail so that is in spec

Next is a full physical inspection of the oxygen sensors and their wiring make sure something did not melt
Check all around intake, exhaust engine with good brite flashlight check all wiring fuses hoses etc

Next is smell your oil, does it smell like raw fuel?

If everything checks out then I would be removing my intake plenum so I could get in there and inspect all air ducking and plumbing to and from including the fuel rail


Something went south

I hooked a scanner this morning while it was running (it almost instantly died) but its showing my o2 sensors are running a incomplete circuit the downstream is showing nothing while upstream are barely anything at the moment

 

[410Fortune]

Check all fuses for the 02 sensors

The 02 sensors are not used for fueling until the pcm switches when it sees proper water temp

But you still should see them “switching” on the scanner I wonder if you just lost an 02 sensor…
But usually that would give you am02
Sensor circuit code not a rich or lean code which indicates the sensors are actually sensing”

 

[Zackie]

All fuses are good, This is such a weird problem.. I still think I may have a bad converter but I'm gonna do other tests before I do anything to check that

 

[Zackie]

All fuses are good, This is such a weird problem.. I still think I may have a bad converter but I'm gonna do other tests before I do anything to check that

I just scanned it again as well the codes swapped po172 po175

 

[410Fortune]

Ah ok
72 and 75
Makes way more sense

Rich both banks

For some reason it could be dumping fuel
I would check pulse at each injector /
Listen to them open /tick

Do you have the factory mas sensor still?

The intake has to come off
I would check for fuel in the vacuum line on the pulse damper
Inspect the injector o rings and seats
Plan on bench testing injectors and intake gaskets at the very least
It sounds like the new injectors are bad or something went bad w the install

Did the sohc engine start making any noises? Would it could it have jumped time? How many miles?

 

[Zackie]

'Unfortunately I can't pull the intake myself with my current area major work is forbidden (which sucks.) So I'm most likely gonna have to get it taken to a dealer so I won't know anything for sure, I usually work on it up at my uncles where he has a lift but that option isn't available at the moment so I'll keep updates going on this one

 

[Zackie]

Ah ok
72 and 75
Makes way more sense

Rich both banks

For some reason it could be dumping fuel
I would check pulse at each injector /
Listen to them open /tick

Do you have the factory mas sensor still?

The intake has to come off
I would check for fuel in the vacuum line on the pulse damper
Inspect the injector o rings and seats
Plan on bench testing injectors and intake gaskets at the very least
It sounds like the new injectors are bad or something went bad w the install

Did the sohc engine start making any noises? Would it could it have jumped time? How many miles?

I just got home for work and I can answer as many of these as I truly can, Intake as I said can’t come off atm due to HOA rules, MAF sensor was replaced when this issue started, Fuel injectors are relatively new, I have no way to check them for damage at the moment, Currently has 119K miles and it’s not making any engine noise, O2 sensors are only reading upstream voltage but nothing downstream