P0174!!

[Jlivi21]

1996 Explorer Sport (V6, OHV, manual)

P0174

Bad gas mileage, randomly shutters, and loss of power.

Have Done:
Changed O2 sensor throwing the code (Bank 2, Sensor 1)
Retorqued intake manifold bolts (Gaskets had been changed due to prior head gasket replacement)
MAF sensor has been cleaned
No vacuum leaks!

Not sure what else should be done? HELP!!

 

[drbenz]

How old are the sparkplugs and wires and are any of the plug wires damaged?

 

[SoNic67]

Fuel filter? Read the live data, maybe the other bank is lean too (not enough to trigger a code)?

 

[Jlivi21]

Changed the plugs a while back. I'll check them again. I'm definitely changing the fuel filter! let ya know if it fixes the problem!

 

[Jlivi21]

Fuel filter didn't do it. Getting Ford O2 sensors for Bank 1. Hopefully, this will do it. I'll update.

 

[Jlivi21]

Okay, so after replacing all the O2 sensors, the code is still appearing.

Bucking and horrible gas mileage.
Garage said no vacuum leaks.
It's almost like my gas is being drained out when it's parked on a downward slope. Ya know when you park it on this angle, the gas gauge will go down when you start it up, but when I level back out... it pretty much doesn't go back up to where it was when I shut it off. Don't know if that means anything, but it's just something that I have noticed.

The bucking just happens whenever it feels like it. Good days and bad, but regardless, I'm still getting 13 mpg, if I'm lucky.

Just P0174, nothing else.

Once more, what I have done....
Changed all 3 O2 sensors
Changed fuel filter
Cleaned MAF
Checked for vacuum leaks

Help!!!!!

 

[Jlivi21]

Spark plugs were changed about 8 months ago. Shortly after, probably within a month, my code appeared. Something up with the plugs, wires, or coil pack?

 

[barbaroja]

You are describing symptoms of the EGR system may be failing. There are threads on how to check the EGR valve (u need a vacuum gun). Please also check the DPFE sensor and the hoses that connect to it. Mine was shot, I just tried to unplug a hose because it was bent and the sensor broke like a piece of toast. Obviously it was heat damaged.

 

[Jlivi21]

A little trick my dad taught me for testing the EGR, I removed the vacuum line from the EGR Valve and plugged it with a screw. If I noticed any difference, then the EGR isn't it, but if there is no difference, then that is the next step.

So I have been driving around like this for about 45+ miles, with no difference, besides that I haven't been noticing the bucking (but there have always been good days and bad days with the bucking, so basically, everything is the same.)

Curious, I plugged in my OBD II and it read a pending code P0401 EGR Flow Insufficient.

The check engine light hasn't come on yet, but it is obviously bound to happen. Oddly, there is no more P0174 since I cleared the code and plugged the EGR hose. Usually, P0174 would be pending in no time after clearing the code.

So would this mean that the EGR Valve is bad. My way of seeing it is maybe P0401 overtook P0174. Maybe the EGR Valve is just clogged up or something, but not enough to throw the code. What do you guys have to say? Should I swap out the EGR Valve for sure? And are there any other things that I should swap out at the same time? Thanks!

 

[barbaroja]

Check the shape of the DPFE sensor hoses. Those should not be bent. Also borrow a vacuum pump to test the EGR.

Here:
http://easyautodiagnostics.com/ford_egr_test/ford_egr_valve_3.php

 

[PatrickMel]

Any updates here?

 

[410Fortune]

from 12 years ago!

smoke test to find any leaks around base of intake or vacuum lines
fuel pressure test, especially when warm
look for exhaust manifold leaks on bank 2 side (drivers)
Large EGR o ring leaking?
check your work..... if head gaskets just replaced then all gaskets and parts associated with that job are suspect

as a mechanic you learn over the years, to check where you were just working, FIRST