99 5.0 EGR problem - need some advice

[SSDavies1]

I have a 99 Mountaineer, 219,000 miles. It's been problem-free under the hood, but i recently picked up a CEL, P0401, insufficient EGR gas flow. I've cleaned all the passages, replaced the DPFE, the EGR control solenoid and the EGR valve. No luck, the light comes back on after about 80 miles. Any suggestions? I now don't think there's a gas flow issue, I'm now wondering if I have a control module or some other sort of electrical problem. Very strange.

 

[crunchie_frog]

I guess you verified the hoses going to the dpfe sensor are not leaking, the ports that these hoses connect to on the EGR tube are not plugged, and that the hoses are connected correctly (two hoses, two ports on the dpfe sensor, two choices).

 

[1997XLTRollover]

Just had this problem in my 98 F-150 with 235k miles after I had the radiator support replaced. Long story short I had a huge vacuum leak. The repair guys forgot to hook back up a hose. Fixed the leak and my EGR worked again. So just double check all your vac connections to be sure that's not where your problem is.

 

[SSDavies1]

Will do, thanks

 

[SSDavies1]

I guess you verified the hoses going to the dpfe sensor are not leaking, the ports that these hoses connect to on the EGR tube are not plugged, and that the hoses are connected correctly (two hoses, two ports on the dpfe sensor, two choices).

Yes, the vacuum lines are correctly attached, and I have verified a good vacuum source and engine stumble when the EGR is forced open. Apparently there's a fuse that I need to check to verify solenoid operation. I'll do that this am and post an update.

 

[Turdle]

Cracked egr tube or exhaust leak?

Exhaust manifold leaks are very common.

 

[SSDavies1]

Cracked egr tube or exhaust leak?

Exhaust manifold leaks are very common.

Tube and manifold seem to be fine. I presume I would be able to hear a manifold leak, correct? The fuse that controls the solenoid circuit is good (see prior post). I'll keep working on this until I find the answer and post it. I was able to get an emissions inspection waiver, so all is well for now.

 

[morbid81]

5.0's are notorious for manifold and egr tube leaks. You will hear a ticking upon acceleration after a cold start. Had mine fixed earlier this year

 

[SSDavies1]

5.0's are notorious for manifold and egr tube leaks. You will hear a ticking upon acceleration after a cold start. Had mine fixed earlier this year

Where was the leak, do you know?

 

[morbid81]

egr tub was leaking, sorry dont get on here much any more hope you got this resolved

 

[SSDavies1]

egr tub was leaking, sorry dont get on here much any more hope you got this resolved

The issue is not yet resolved. I was able to get an emissions inspection waiver, so I'm good until next fall. I'll check for a leak, but I don't think that's it. Everything is checking out ok in terms of vacuum/solenoid/valve operation. I'll post the solution once I get there. It's not a priority right now.

 

[SSDavies1]

All - just want to to post the resolution of this issue. Not long after my last post, I picked up codes for a camshaft position sensor problem, and then an ignition misfire. I replaced the sensor, but the codes did not clear. Since the spark plugs may or may not have been original (note mileage in my original post), I replaced them and reset all the codes. That did it, including clearing the original EGR CEL. The plugs were obviously in very bad shape, and perhaps were the cause of insufficient exhaust flow. Anywho, I wasted a lot of time and some money chasing a problem that was probably the result of lousy maintenance practices....vehicle is running fine. Will avoid any spark plug endurance testing in the future...