Dreaded insufficient EGR flow. I've read I should clean the EGR ports.
I can't really find where these are? I took the throttle body off.
What I should do with this thing? I also get a hesitation on initial take off.
1999 F150 4.2 V6 ... 160k miles on it. Runs good otherwise.
My 2001 F-150 came up with this code and I changed the EGR valve cleared the code and it returned 15 miles later. The truck only has 30K miles and the warranty expired 24 May.
View 14 RepliesHas a P0401 code EGR unSufficient flow. Ive read several things that it could be, from a DPFE sensor to the EGR valve it's self our that the port going into the TB could be plugged. Truck drives fine does not have a miss or anything noticeable when driving other than the CEL, trucks a 4.6 with 200k on it. Forgot to mention it sometimes gets a P0455 code but i assumed that is gas cap. or could it be related?
View 7 RepliesMy '96 4L developed the infamous P0401 insufficient EGR gas flow code 6 months ago. Rough running. Forgot to license it, now the St. Emissions Test was due before I could get new tabs issued. Finally got some warm dry weather to work on it. Started with the electrical measurements per DPFE graph of EGR flow vs electrical output to the PCM.
Showed the DPFE sensor failed, low V output max 2v. The old OEM aluminum body DPFE sensor was still in the old girl after 16 years. Corroded internally and ext., one hose nipple almost corroded off. Eureka. Put in a new Motorcraft plastic body upgrade. Same darn code.
Retested everything from the EGR vacuum valve that feeds the EGR valve to the new DPFE and then the EGR tube from the exhaust pipe. All tested ok electrically and leak wise. No fresh air leaks in the EGR V or EGR tube.
All pointed to restriction in EGR gas flow when PCM demanded it. Ran small stainless steel wire down the upper EGR tube line nipple to the EGR orifice trying to clear carbon build up, still the same P0401. Poured several cups of paint store acetone down each EGR tube hose with engine off and at 2k rpm to emulsify and dissolve the exhaust carbon out. Engine vacuum sucked the acetone up thru the EGR valve also cleaning it internally.
Let set overnight and took out for test drive. Still P0401. Almost ready to drive the green beast to the crusher of death.
Poured more acetone in the EGR and let set for 2 days prepared for the emissions station test failure then repair at emissions cert. shop with a shop waiver for no effective repair. Decided that the EGR tube or EGR valve were leaking fresh air, rusted and corroded. The end nuts on the tube were rusted away. EGR tube NLA from any source.
Went to the emissions test today and passed flying colors. NO P0401, drove all day on business. Got relicensed.
The old girl runs and drives like a dream, she's actually parked and sleeping in the garage tonight all pretty and shiny with a wash and wax job, got a reprieve from the Jaws of Death
I recently purchased a 2000 Accord coupe v6 with 180k on the clock. I've noticed the gas mileage isn't what it should be. The check engine light was on when I bought it turns out it was a p0401 code. I was told at the dealership insufficient egr flow would cause the car to run rich. So I figured that's what is killing my gas mileage. Well after cleaning the egr port, replacing the egr valve, changing the spark plugs and changing the oil there is no improvement.
View 7 RepliesI am preparing to combat the old P0401, Insufficient flow issue. While looking at the steps in Alldatadiy the very first decision essentially forks on "EGR System Module" or "Others".
I am just guessing that, since the choice is there, some engines will have one and some will have the other. But I thought I'd come here and see if I could learn a little more about it.
How can I tell what my truck has? I'm sure there is some difference...
The truck in question is a 2004 6.0L Excursion, stock original turbo, no tunes, and EGR cooler delete done 1 year ago. Scanned for codes and none were found except for EGR insufficient flow P0401 code which is due to the EGR cooler delete.
Upon startup (no issues there) the VGT reads 67-70, now once the truck goes to high idle to warm up (1150 or so RPM) the VGT slowing climbs to 85 and stays there. If I blimp the throttle or step on the brake it goes back to 67-70 at normal idle. This has been happening for a few months now on a regular basis. I have checked the MAP, BARO, and EBP readings at KOEO and they are all within 0.6 of each other (14.4-15.0). The EBP tube was checked and cleaned (no buildup present)..
I just got a Check Engine light on yesterday. I went to Autozone and got an OBD-II Trouble Code: P0401, Insufficient EGR Flow Insufficient. The Autozone guy showed me an EGR valve for $164 and said it maybe blocked or something. I also checked with a friend who says that as long as the engine is not overheating it should be okay for driving for now.
So the far the car runs just fine, I haven't experienced any issues out of normal. Does the code mean the value need to be replaced?
EGR insufficient flow. EGR valve was pretty bad looking seemed a bit sticky when opened so I replaced it along with gasket. Reset the computer but check engine light came back on code p0401 again. I know you can test by pinching the yellow striped hose at the throttle body to see if the solenoid is bad. The engine will stumble a bit when you pinch it closed, or so I am told. However when I pinch the hose, nothing happens. I do notice that the car does idle kind of roughly.
View 1 RepliesI just bought a 1997 ford f-150 4x4 with 4.6 motor. the check engine light came on. My diagnostic tool reads code 401 (egr insufficient flow). I've replaced on the parts on the egr side of engine. light still on. could it be a leak in the vacuum lines. I don't see any wear.
View 4 RepliesI have a 2000 Ford Ranger 3.0L engine, 2 wheel drive, with automatic transmission. Check engine light came on about 3 months ago. checked with scanner and P0401 EGR flow insufficient came up. cleared it and it came back. truck seems to be running fine. I didn't take autoshop as a kid, so i probably will need a little hand holding on this one.
View 14 Replies1997 F150. 6Cyl, 4.2L, 139K miles. The truck threw a P401 code(EGR Flow insufficient)and won't pass emmisions here (due by the end of March). So far this is what
I've done : Replaced EGR, replaced DPFE, replaced EVR solenoid, removed throttle body manifold under EGR and cleaned all ports (they weren't even dirty), cleaned and checked all vacumn lines from the DPFE to the main EGR tube from exhaust. Also cleaned the main EGR exhaust tube.
Everything is squeaky clean. All voltages going to the DPFE/EGR are spot on and the whole system seems OK. But the P401 code literally comes on almost immediately (less than 2 miles) after clearing the code (I hooked up my scanner to see how long).
I've researched the heck out of P0401.... I have an 04' F250 w/a 6.0, 61k miles, completely stock. I have been getting a reoccurring P0401 EGR flow CEL. I've checked all the fittings and tubes and see no cracks or breaks. I've checked the exhaust system and no signs of leaking soot anywhere except on the passenger side exhaust manifold, there is some minor deposits of soot near the first two cylinders, but that's it.
Everything else looks good and I can't hear any hissing either. I am not getting any white smoke from the exhaust. I pulled my EGR valve and looked at it, it looked fine. I cleaned it off and put it back in. Then I got a new one just to see if that fixed it. I am missing a little coolant. I'm adding maybe a few cups of coolant every few weeks. Truck is always serviced and only repairs was Ford replaced the EGR valve in 2008. When I pull my EGR valve, it is slightly moist in the housing but not wet and no sludge. Again, the EGR valve had a nice layer of soot, no build up or sludge on it....
1997 Ford F150. 6cyl, 4.2L 138K. Have CEL on and code reads: "P401 - EGR Flow insufficient". I replaced the EGR valve and checked the ports leading into them and they seem clean. There is one additional component called "EGR feedback sensor" which I really don't want to replace unless I can determine that this is faulty.
View 1 RepliesI have a 2002 F-150 that is showing a code indicating "EGR insufficient flow". I replaced the EGR valve and cleared the light/code, but the "check engine light" keeps coming back on and code indicates the same problem. What may be causing the light to keep coming on, even after replacing the EGR valve?
View 14 RepliesI got an 0401 EGR Flow Insufficient last week. I cleared it and it showed up again after a couple of days. I replaced the EGR Valve and the 0401 reappeared. I replaced the DPFE and the code did not reappear. Great!
About a week later, I got an 0402 EGR Flow Excessive. New EGR Valve. New DPFE. The hoses to and from the DPFE to the tube look decent. They don't appear to have any build up inside. Code 0401 or 0402 to the tube?
My first instinct is to replace the EGR valve again, assuming the one AutoZone gave me is stuck open. Is there any servicing I can do to it first? Like maybe soak it in carburetor cleaner? Or spray it with WD-40?
So here's the background. I recently bought this truck. It's a 97 Ford f150 4x4 4.6l 99w vin code. Anyway Driving it home got a p0401. No problem. I Applied vacuum from other vacuum source to EGR engine stalls. So to me passages are clean in the throttle body. I checked to verify and indeed passages are clean. No while doing so I noticed no vacuum was making its way to the dose valve thing. Strange.... So took the line that runs to the passenger fender to dose off and it was impossible to blow air through.
So I cut out the clogged section found solder in the line. I filled the gap I now created using some 5/32 vacuum line reconnected to test and to my anvil still not vacuum. So I disconnected it again. Went directly to where the yellow/orange dose vacuum line connects to at the passenger fender and to my surprise no vacuum there either. No my question is. Am i suppose to have constant vacuum to the dpse or I'm I just being an idiot. And two if I am suppose to when the vacuum line runs into the passange fender where does it go from there and could I have a major issue in my hands?
On my 98' f250 4.6L 4x4 .. My check engine keeps going off and on, I finally pulled the code and its the P0401. The truck pings and knocks now and than and idles a tiny bit rough sometimes but overall runs good and gets the same mpg it always gets.....is this a bad egr valve?
View 2 Replies1996 Toyota camry le 4 cylinders has code po401 does it damage engine what will it do. Insufficient exhaust flow...
View 3 RepliesI've had a 0401 code on my truck for the last two years. I've replaced the EGR valve and the dpfe sensor a couple of times, with fomoco parts. Ive also cleaned out the egr tube that comes off the exhaust manifold. In this time I also discovered a couple of vacuum leaks and replaced those. I changed the pcv valve, tried running 93 octane gas, and had a mechanic friend run a special smoke through the vacuum lines to find more leaks. Also put a brand new gas cap. I have an obd computer and cleared the code repeatedly but the light always returns.
View 14 RepliesHave a p0401 code which I need to diagnose and solve. However, I don't believe the symptoms are indicative of the EGR system. Its a 1999 4.6L auto approximately 200k miles. Truck runs fine until it warms up, and then occasionally it begins to act like its missing under load. steady state on the freeway it may have an occasional miss, but put a load on the motor and the miss becomes real bad. This doesn't seem to me to be symptomatic of a P0401 code, but I don't really understand the EGR system enough to be sure. Searching on the forums for other p0401 codes doesn't seem to have the same symptoms.
View 10 Replies