SPONSORED LINKS

Code P1401

Tiny
CBRASSO
  • MEMBER
  • 2001 FORD F-150
  • 4.6L
  • V8
  • 2WD
  • AUTOMATIC
  • 185,000 MILES
Had a code P1401 so I replaced the EGR pressure sensor which cleared the light. Few days later I got a code P0401 for insufficient flow. The 2 hoses from the sensor had deteriorated and pieces clogged up the pipe they connect to. Cleaned that out and code cleared but now I have a noise like a howl in my air box area and the hose from the evap system to the back of throttle body collapses. Could it be the EGR valve itself? Let me add I’d removed EGR valve and the ports were completely clogged up solid and I did clean it all out. I have pictures below of before and after. Thanks
Images (Click to make bigger)
Thumb
Thumb
SPONSORED LINKS
Tuesday, January 14th, 2020 AT 5:16 AM

17 Replies

Tiny
BMDOUBLE
  • MECHANIC
  • 1,139 POSTS
The hose at the rear of the throttle body is the PCV tube elbow and is extremely common to collapse over time just due to normal deterioration of the rubber from exposure to oil. The howl noise on these trucks is usually due to the idle air control valve sticking and will cause a droning noise, the PCV hose collapsed can intensify this noise also. Sometimes you can give the idle air control valve a tap with the handle of a screwdriver and the drone will disappear.
SPONSORED LINKS
Was this
answer
helpful?
Yes
No
Tuesday, January 14th, 2020 AT 9:08 AM
Tiny
CBRASSO
  • MEMBER
  • 43 POSTS
BMDOUBLE thanks for the reply but I’m talking about this hose that’s circled.
Image (Click to make bigger)
Thumb
Was this
answer
helpful?
Yes
No
Tuesday, January 14th, 2020 AT 2:01 PM
Tiny
BMDOUBLE
  • MECHANIC
  • 1,139 POSTS
Oh okay, no problem! Yes that is the evap line and they collapse due to age and exposure to fuel vapors. I actually just replaced the one on my expedition, just carefully split the line with a razor blade at the green fitting and remove the fitting. Replace the line with fuel hose then retest to make sure that it doesn't collapse. If there is still an issue with the line collapsing, the canister could be restricted or the a restriction between the tank and the purge valve, but the canister is the prime suspect.
Was this
answer
helpful?
Yes
No
+1
Tuesday, January 14th, 2020 AT 7:08 PM
Tiny
CBRASSO
  • MEMBER
  • 43 POSTS
Okay. I did replace it but with regular heater hose. I’ll replace it with fuel line. And if still persists I’ll do as you said and report back. Thanks again.
Was this
answer
helpful?
Yes
No
Tuesday, January 14th, 2020 AT 7:56 PM
Tiny
KEN L
  • MASTER CERTIFIED MECHANIC
  • 48,363 POSTS
BMDOUBLE is one of our best! Please let us know what happens.
SPONSORED LINKS
Was this
answer
helpful?
Yes
No
Saturday, January 18th, 2020 AT 3:26 PM
Tiny
CBRASSO
  • MEMBER
  • 43 POSTS
BMDOUBLE, the box next to the canister had no fresh air hose and had gotten clogged up with dirt. I blew it out with low pressure air and cleaned it out really good but the problem appeared again. I read that a faulty PCV valve would also cause this is it possible? Problem started after I changed hoses for EGR back pressure sensor and sensor and cleaned out the EGR passages. Any idea what could be happening?
Was this
answer
helpful?
Yes
No
Sunday, January 19th, 2020 AT 12:14 AM
Tiny
KEN L
  • MASTER CERTIFIED MECHANIC
  • 48,363 POSTS
Yes, a bad PCV valve can cause EGR issues. Here is the location so you can change it out. Also I have seen clogged catalytic converters cause this issue as well. Check out the diagrams (below). Please let us know what you find.
Image (Click to make bigger)
Thumb
Was this
answer
helpful?
Yes
No
Monday, January 20th, 2020 AT 10:13 AM
Tiny
BMDOUBLE
  • MECHANIC
  • 1,139 POSTS
If the box next to the canister was clogged, then the canister itself could be clogged which is common on higher mileage vehicles. If the evap line is collapsing, it would be from a restriction on the evap side starting at the purge valve then the lines that go under the truck then to the canister itself. What you can do is verify that the purge valve is not clogged by grounding the lg/bk wire then disconnecting the white fitting at the valve to see if you can feel any vacuum there, if not then the valve has failed. The PCV should have nothing to do with this line being collapsed because it is parallel to this vacuum circuit, kind of like 2 straws in a drink.
Was this
answer
helpful?
Yes
No
Monday, January 20th, 2020 AT 11:57 AM
Tiny
CBRASSO
  • MEMBER
  • 43 POSTS
Okay, I will do that this evening after work and respond back and let you guys know. Thanks
Was this
answer
helpful?
Yes
No
Monday, January 20th, 2020 AT 12:38 PM
Tiny
CBRASSO
  • MEMBER
  • 43 POSTS
BMDOUBLE just to be sure. Exactly how would I ground out the lg/bk wire?
Was this
answer
helpful?
Yes
No
Monday, January 20th, 2020 AT 12:45 PM
Tiny
BMDOUBLE
  • MECHANIC
  • 1,139 POSTS
You back-probe the wire at the connector with a needle, or small wire as long as it fits into the connector and use a jumper wire straight to a clean piece of metal. If you have a hard time fitting something into the connector just take a razor blade and shave off a small piece of the wire's insulation then make contact with a jumper wire from there to ground, you should hear a click then a hiss from the vacuum being present now at the unhooked port of the purge valve.
Was this
answer
helpful?
Yes
No
Monday, January 20th, 2020 AT 2:29 PM
Tiny
CBRASSO
  • MEMBER
  • 43 POSTS
Okay. I wasn’t able to check last night but will ASAP and let you know the findings.
SPONSORED LINKS
Was this
answer
helpful?
Yes
No
Tuesday, January 21st, 2020 AT 5:46 AM
Tiny
BMDOUBLE
  • MECHANIC
  • 1,139 POSTS
No problem! We're here for ya!
Was this
answer
helpful?
Yes
No
Tuesday, January 21st, 2020 AT 7:43 AM
Tiny
CBRASSO
  • MEMBER
  • 43 POSTS
Bmdouble, I did as you stated above and I do have vacuum and the motor surges. So I take it the purge valve is okay?
Was this
answer
helpful?
Yes
No
Sunday, January 26th, 2020 AT 9:24 AM
Tiny
BMDOUBLE
  • MECHANIC
  • 1,139 POSTS
Yes, that verifies that the purge valve is good, but verifies also that there is a restriction more than likely inside of the canister, that would be the only explanation for the vacuum line to collapse, kind of like the straw inside of an extra thick milkshake scenario.
Was this
answer
helpful?
Yes
No
Sunday, January 26th, 2020 AT 3:39 PM
Tiny
CBRASSO
  • MEMBER
  • 43 POSTS
Okay, when I removed the canister to check the vent solenoid which clicked when connected directly to 12v when I blew into the hose air came out the other one. So I’d assume the restriction is between there and the purge valve.
Was this
answer
helpful?
Yes
No
Sunday, January 26th, 2020 AT 8:24 PM
Tiny
KEN L
  • MASTER CERTIFIED MECHANIC
  • 48,363 POSTS
We have ventured off topic in this thread. please start a new thread for this issue. Please post your new question here, you must be logged in. Please only include the P1404 isuse on this thread.

https://www.2carpros.com/questions/new

Cheers, Ken
Was this
answer
helpful?
Yes
No
Wednesday, January 29th, 2020 AT 10:25 AM

Please login or register to post a reply.

Related P1401 Content

VIEW MORE

Sponsored links