I Have A 1998 F-150 2wd 1/2 With The Triton 4.6l V8 And My Check Engine Light Has Been On So I Put A Code Reader And I Got Codes;

401 Insufficent Egr Flow

402 Egr Flow Excessive At Idle

442 Leak In Evaporative System Detected

So To Fix These What Do I Need To Do. For The Leak Im Just Gonna Go To Pep Boys Cause I Do Not Wanna Undertake The A/c System. But For The Egr Do I Need Just A New Valve Or Sensor?
Thank You For Your Help

 

Chances are pretty good that the EGR codes are caused by a bad DPFE sensor if the trucks runs well. Your dealer probably has lots of those in stock as it's a common problem. I would get a genuine Ford one because they have been upgraded a few times lately.
Here is what the manual says about the P0442..........

Continuous Memory Diagnostic Trouble Code (DTC) P0442 indicates that a fuel vapor leak has been detected [as small as 0.10 cm (0.04 inch)] in the Evaporative Emission (EVAP) system. Possible causes:

After market parts and accessories nonconforming to the EVAP system specifications.
Damaged, cross threaded or loosely installed fuel filler cap.
Small holes or cuts in fuel vapor hoses/tubes (EVAP canister tube, EVAP canister outlet tube or EVAP return tube) in the EVAP system.
Loose fuel vapor hose/tube connections to EVAP system components.
EVAP system component [EVAP canister purge valve, fuel tank pressure (FTP) sensor, canister vent (CV) solenoid, fuel vapor control valve tube assembly or fuel vapor vent valve assembly] seals leaking.
CV solenoid partially open when commanded closed.
EVAP canister leaking.
Check for presence of fuel filler cap.
Verify that the CV solenoid is properly seated on the EVAP canister (if possible).
Visually inspect for cut or loose connections to fuel vapor hoses/tubes in following locations:
EVAP canister to EVAP canister purge valve.
EVAP canister to fuel vapor vent valve assembly.
fuel vapor control valve tube assembly to fuel tank (if applicable).
Check for fuel filler pipe damage.

 

FWIW, EGR systems should be covered by the 8 year/80K mile federally mandated emissions warranty. Check with your dealer.

Steve

 

Yes, how many miles on your 98?
PO442 on mine was a bad gas cap. $20.00 dollars later and 1 new locking cap and no more code.
Racerguy what is a DPFE sensor? If it is not that I would try cleaning the EGR.
Good luck.

 

DPFE is Differential (or in some books Delta) Pressure Feedback EGR sensor.
It senses how much Exhaust Gas is flowing through the EGR by looking at the Differential across an orifice in the EGR tube. It tells the PCM (Powertrain Control Module) how much EGR is flowing so it can figure out what the timing and fuel delivery should be set at.
This is a pretty generic picture of a DPFE. If you follow the 2 rubber hoses that run up off the tube from the driver's side exhaust manifold to the EGR valve you'll find it at the top.

 

Thanxs, I love this site.
Tony J.

 

i read a few of these messages. I have a Ford Expedition 4.6l V8 triton and the "CHECK ENGINE" light is on. I checked the computer code and it read: 401 Insufficent Egr Flow. I have dual flowmasters on the EXPY and ever since this problem occurred i get less Horsepower (at least it feels like it), and also seems to waste more gas? This is common for this type of problem?

QUESTION: HOW MUCH WOULD THIS COST TO GET FIXED? THANKS GUYS.

 

Rebble187,
It probably won't cost you anything if you have a few hours to spend on it. Check out this link.
https://www.ford-trucks.com/forums/showthread.php?t=248921&highlight=P0401
Good Luck!

 

You mean I just wasted $40, and 5 knucklebusting hours changing the EGR Tube on my 98 F150 with 52K miles????

Grrrrrrr!

 

Probably not. I should have qualified that response to the specific components that might be covered under the emisssions warranty. It varies somewhat by model year.

Steve

 

I would check that link mentioned above. I have 150,000 miles on my 97 f150 and when i took the throttlebody off the two egr ports were completely full of carbon buildup. When i started i had a hard time fitting a coat hanger in the port after i was done i could fit the tip of my pinkie. It only took about and hour but i already knew how to take off my throttle body, but it was worth it. My Check Engine Light was on for about a year to year and a half. I worked on it two weeks ago and haven't had a problem since.

 

hello i recently bought a 98 expedition. I kept on getting a 401 code so i changed the dpfe then i changed the egr valve still had the code so after some research and talking to a friend who is a ford mech he told me that the ports from the throttle body that feed to the egr valve get plugged. Lo and behold i removed the throttle body and the two little ports that go to the egr valve were plugged almost solid. I cleaned these out and put everything back on guess what? the check engine light went off after driving it for awhile. Don't know if this helps but thought i would share.