P0174 code on 01 V8

fbird18

fbird18

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Just like the title says, I am having a problem and that is the code the autozone scanner got. I searched already on the subject and all I found was V6 info. The car starts fine, drives and accelerates and shifts fine, but idles like a 84 camaro with aggressive cams :) and you can smell fuel outside the car.

The autozone scanner spit this out:

Definition:
Fuel trim bank two condition.

Explanation:
The ECM had detected a rich or lean air/fuel ratio condition on engine bank two.

Probable cause:
1-If bank one and two are set together suspect a fuel pressure condition or MAF sensor fault.
2-Failed HO2S21 (heated oxygen sensor - bank 2 sensor 1)
3-Ignition misfire condition
4-Fuel Injector problem
5-Engine mechanical condtion
(the guy said it was cylinder 4 with the problem, but I don't see anywhere on the printout pointing at cylinder 4)

Is there a good place to start checking things without diving into replacing fuel injectors or MAFs? If it makes any difference, two weeks ago replaced the DCCV. Did the clockspring last week. All injectors and all COPs replaced 2 years ago. Also have 149,00 mi on the odometer. Any help is greatly appreciated I would love to figure this out this weekend.
 
fbird18 said:
Just like the title says, I am having a problem and that is the code the autozone scanner got. I searched already on the subject and all I found was V6 info. The car starts fine, drives and accelerates and shifts fine, but idles like a 84 camaro with aggressive cams :) and you can smell fuel outside the car.

The autozone scanner spit this out:

Definition:
Fuel trim bank two condition.

Explanation:
The ECM had detected a rich or lean air/fuel ratio condition on engine bank two.

Probable cause:
1-If bank one and two are set together suspect a fuel pressure condition or MAF sensor fault.
2-Failed HO2S21 (heated oxygen sensor - bank 2 sensor 1)
3-Ignition misfire condition
4-Fuel Injector problem
5-Engine mechanical condtion
(the guy said it was cylinder 4 with the problem, but I don't see anywhere on the printout pointing at cylinder 4)

Is there a good place to start checking things without diving into replacing fuel injectors or MAFs? If it makes any difference, two weeks ago replaced the DCCV. Did the clockspring last week. All injectors and all COPs replaced 2 years ago. Also have 149,00 mi on the odometer. Any help is greatly appreciated I would love to figure this out this weekend.
Click to expand...

I would check all your connections to your fuel injectors. My car did something very similar and it ended up being a loose injector. I think that happened to DeMarko too. check there then post back your results. Good Luck
 
SlickLS said:
I would check all your connections to your fuel injectors. My car did something very similar and it ended up being a loose injector. I think that happened to DeMarko too. check there then post back your results. Good Luck
Click to expand...

Thanks I'll check all those connections. When I replaced the injectors I remember about half or more of the plastic clips broke off, so that's a good possibilty. I looked for de-markos similar problem be didn't seem to find it. Anyone else have any suggestions? I also looked at my MAF sensor, that couldn't look any newer so I doubt it's dirty.

On another note, I took off my intake tube and at the throttle body connection, it was filthy inside there. I cleaned that up. Is that a bad thing or just normal?
 
That problem demarko is discussed under his timing chain teardown thread I think.
 
Thanks ill check it out.

I just got it read again and can now add codes:
P0113, P0301, P0304

:confused:
 
I checked all the injector wires, and they were all good. I was only able to check the passenger side coils today. No oil in there and they all had roughly the same voltage. Ideas anybody?
 
P0174- bank 2 is the passenger side of the car, and it is the 02 sensor that is bad, could also mean the MAF (Mass Air Flow) Sensor is dirty or faulty, but most of the time its the 02 sensor


P0113 - means your Intake Air Temperature (IAT) sensor is sending a voltage signal back to the PCM that is too high (over 4.6 volts)

As noted, the IAT is a thermistor device in which resistance changes with temperature. The electrical resistance of a thermistor decreases as the temperature increases, and increases as the temperature decreases, (proportionally in each case). This varying resistance affects the voltage drop across the sensor terminals, which allows for a voltage signal to be sent back to the PCM corresponding to temperature.

The voltage signal that is sent back to the PCM is equal to the Reference Voltage (VRef, 5 volts) minus the aforementioned voltage drop across the fixed resistor. That is why an open in the circuit between the PCM and the IAT will result in "too high" voltage signal at the PCM (i.e., 5 volts). In addition, corrosion in the circuit would tend to add resistance and hence result in higher-than-normal voltage at the PCM because of the signal being based on voltage drop.

In any case, if the circuit checks out OK, then it's either the IAT sensor at fault, or the PCM.

P0301, P0304 - * Faulty spark plug or wire
* Faulty coil (pack)
* Faulty oxygen sensor(s)
* Faulty fuel injector
* Burned exhaust valve
* Faulty catalytic converter(s)
* Running out of fuel
* Poor compression
* Defective computer
(most of the time its the coil)
 
Thanks Lincoln Jealous, very informative. Problem is I think that all went over my head :). Any way to dumb that down for me? Like say if I can check the resistance at the IAT or 02 sensors? Or with the given codes if I should just replace them? Sorry for the questions, I just suck at diagnosing problems. I can fix just about anything, but figuring out what is wrong is not my forte. Thanks in advance.
 
The P0113 code is a good clue that you have an issue with your MAF, or the wiring to it. (The IAT is part of the MAF.) Start there.

Next, think about replacing the COPs and plugs on the right bank. If you're smelling raw gas, it almost has to be that cylinder(s) aren't firing always.

What do you mean by measured the coil voltage? Measurements of primary voltage, or of coil resistance will not detect the internal high-voltage breakdown failure mode of the coils.
 
The MAF looks brand new inside and out, could it still be bad? Also, the IAT is the smaller sensor just after the MAF on the intake tube right? If it is, then that also looks brand new. Is it possible that a bad o2 sensor would casue the P0301 and P0304?

We took the coils after pulling them out of cylinders 1-4 and took the ohms meter to them. They all read about 6.15. I forget what setting it was on, but they all read the same thing. I have no idea if that actually means anything though.
 
fbird18 said:
The MAF looks brand new inside and out, could it still be bad? Also, the IAT is the smaller sensor just after the MAF on the intake tube right? If it is, then that also looks brand new. Is it possible that a bad o2 sensor would casue the P0301 and P0304?

We took the coils after pulling them out of cylinders 1-4 and took the ohms meter to them. They all read about 6.15. I forget what setting it was on, but they all read the same thing. I have no idea if that actually means anything though.
Click to expand...

You must have a gen I.
The fact that the sensors look new, has nothing to do with if they function or not. Also, don't forget the wiring between them and the PCM.
It is unlikely that a bad O2 sensor is causing your misfires.
Resistance readings on these coils are meaningless in as far as detecting failure. All of the bad coils that I have replaced still had good resistance readings. (I know they were bad, the misfires ending after replacing them.) The only way to test them is the stress testing that the dealers do. I assume that you don't have an oscilloscope. Unless you do, the only way you can test would be to substitute known good coils.
 
Yep its an 01. I will replace the MAF and IAT and see what happens. I always thought if they weren't dirty that they would be good, but yeah I guess things do just crap out sometimes. Would the Idle Air Control cause any of this you think? It starts and drives fine. Just idles like sh*t. If none of that works I guess I'll just have to buy a couple coils and replace cylinders 1 and 4.
 
fbird18 said:
Yep its an 01. I will replace the MAF and IAT and see what happens. I always thought if they weren't dirty that they would be good, but yeah I guess things do just crap out sometimes. Would the Idle Air Control cause any of this you think? It starts and drives fine. Just idles like sh*t. If none of that works I guess I'll just have to buy a couple coils and replace cylinders 1 and 4.
Click to expand...

Yes, the IAC could be at least part of the issue. I would at least take it off and clean it. These do get dirty and fail over time. I didn't think about it because I am too used to gen II (no IAC).
 
To check the IAC motor remove the unit, with the wires connected turn the key to the "on" position without starting the engine, the IAC should move in or out. If the IAC motor does nothing it has probably failed, replace it with a new unit and recheck system. Note: while the IAC motor is removed clean (use aerosol carburetor cleaner) the passages the IAC uses to control idle air speed, also inspect the IAC for a build-up on the seating (pointed) end and clean as necessary.
 
Good god, I just got off the phone with the dealer.....:(

MAF = 257.50
IAT = 52.50
COP = 100.89

But with my discount (dealer cost)
MAF = $120.50 + core
IAT = $22.30
COP = $45.82

I have never bought a MAF sensor before, had no idea how expensive they were. And I swear I bought a IAT sensor before and it wasn't that bad. I'm going to call autozone and check them too, but usually thier price is comparable to my dealer cost price.
 
Lincoln Jealous said:
To check the IAC motor remove the unit, with the wires connected turn the key to the "on" position without starting the engine, the IAC should move in or out. If the IAC motor does nothing it has probably failed, replace it with a new unit and recheck system. Note: while the IAC motor is removed clean (use aerosol carburetor cleaner) the passages the IAC uses to control idle air speed, also inspect the IAC for a build-up on the seating (pointed) end and clean as necessary.
Click to expand...

Thank you, very good info. I'll hopefully be doing that soon.
 
fbird18 said:
Good god, I just got off the phone with the dealer.....:(

MAF = 257.50
IAT = 52.50
COP = 100.89

But with my discount (dealer cost)
MAF = $120.50 + core
IAT = $22.30
COP = $45.82

I have never bought a MAF sensor before, had no idea how expensive they were. And I swear I bought a IAT sensor before and it wasn't that bad. I'm going to call autozone and check them too, but usually thier price is comparable to my dealer cost price.
Click to expand...

It's a Lincoln!!!
Get used to it.
 
I have a spare MAF dude. AT least, I'm pretty sure I still do.

I'll check and shoot you a text.

I was saving it for if I ever have any issues with mine. So, what I can do is:

Send it to you. You install it, and see if your issue goes away. If it doesn't go away, send it back. Then at least you aren't out 120 for the part. If it does go away, make me an offer on it.
 
pektel said:
I have a spare MAF dude. AT least, I'm pretty sure I still do.

I'll check and shoot you a text.
Click to expand...

Thanks Pete. I don't really have a problem buying the part and if it doesn't change anything, returning it. But if I do need a new MAF, I might take you up on a trade or barter :) Like say if you do send me the MAF, I could let you continue giving me free detailing advice :shifty: Sound fair to you? :D
 
Lincoln Jealous said:
To check the IAC motor remove the unit, with the wires connected turn the key to the "on" position without starting the engine, the IAC should move in or out. If the IAC motor does nothing it has probably failed, replace it with a new unit and recheck system. Note: while the IAC motor is removed clean (use aerosol carburetor cleaner) the passages the IAC uses to control idle air speed, also inspect the IAC for a build-up on the seating (pointed) end and clean as necessary.
Click to expand...

Hey, do you know this for a fact for the IAC on the LS? (I don't know for a fact one way or the other - my info is all for the gen II.) The reason that I ask is that this is not the way that Ford IAC typically work. In particular, my experience is with the ones on 1991 to 2000 Grand Marquis. They use a solenoid, not a motor. The solenoid opens a small valve that you can't see. This valve uses the pressure differential between the air and the intake manifold to move the bigger air valve that you can see. Because of this, the big valve won't move if the IAC is not connected to a running engine.
I know that some other makes actually use a stepper motor and do work as you describe, that's why I ask if this is generic web advice, or LS specific?
 
Hey Joe

Yep the 01 has the IAC and its does go bad. Been there done that. Should try to clean it first, then reinstall to test results, it's only two bolts. Easy stuff. It is a solenoid.
 
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joegr said:
Hey, do you know this for a fact for the IAC on the LS? (I don't know for a fact one way or the other - my info is all for the gen II.) The reason that I ask is that this is not the way that Ford IAC typically work. In particular, my experience is with the ones on 1991 to 2000 Grand Marquis. They use a solenoid, not a motor. The solenoid opens a small valve that you can't see. This valve uses the pressure differential between the air and the intake manifold to move the bigger air valve that you can see. Because of this, the big valve won't move if the IAC is not connected to a running engine.
I know that some other makes actually use a stepper motor and do work as you describe, that's why I ask if this is generic web advice, or LS specific?
Click to expand...

sorry joe, motor i mean solenoid, your correct about what it is and what it looks like, it is more of a solenoid

222.JPG


333.JPG
 
small update

I replaced the IAT sensor last night and it seemed to make the terrible idle a little better. But it gives me hope that a new MAF will fix the problem. I should be able to pick it up from autozone tonight and install it. Fingers are crossed.

Question about that, should I clear the codes/unhook the battery before I install it? Or do you think it is a plug n play situation and as soon as its in (provided it does fix my issues) everything will be all good? Also is it possible that the P0301 and P0304 codes have damaged those coils and they will need to be replaced anyways?

If there is still an issue, I will try cleaning the IAC. Thanks for your help so far guys.

Oh and yeah I already checked my fuel injector connectors. They were all seated fine.
 
Well I put in a new MAF sensor last night. Didn't seem to do much. It's a little smoother, but still not fixed. Does something like that acheive immediate results or does the computer need to learn that there is a new sensor in there and can take a little time to "correct" itself?

I did check the IAC and it was filthy. Cleaned that with carb cleaner and then plugged it in and turned the key to on to see if it did anything. It made a noise like it wanted to move, but it didn't do anything. So it looks like another $120 part gets put on.

I really need a little assistance here now. How to figure out what is actually wrong.

P0174, P0301, P0304 are the current codes

New IAT sensor - seemed to help a little
New MAF sensor - seemed to help a little
Will be buying a IAC.
Have 2 new COPs

As I replace these things, should I see immediate results? Will I know when a particular part fixes the problem? I feel retarded right now. I have fixed a many things on this damned motor and car and haven't really had as much trouble as I am having now. Thoughts or suggestions please?
 
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