2000 Rodeo code P0401

The MIL light on my Rodeo keeps illuminating with code P0401 "Low EGR flow". I had the EGR valve replaced and it ran fine for a while but came back on less than a week later. It was then found to have a leaking intake manifold gasket (which was still covered by warranty) but the code still came back on less than 24 hours later. This has been going on for about 2 weeks and no one around here seems to know why. What else would cause this code to be returned? Any ideas would be appreciated.

well i really dunno what to tell you, didnt you say your car is still under warranty, have your dealer deal with it, and then if they can't fix it, bitch them out and tell them to get you a new car or something. Otherwise, hm, are you getting the same code everytime??? If so, then it's something in front of the EGR. Then that'll narrow up the gap. If it's different codes, then you'll have a bigger problem, if you could do a check everytime the engine light comes on, then i'll see what i can do to help. Also you might wanna go ahead and reset your ecm if you wanna, hope that'll help, sometimes it does and sometimes it doesnt depends. Good Luck

Hey Fstar1, you've probably long since fixed your EGR problem. If you havn't, from the syptoms you describe, it looks like the exhaust feed tube to the EGR assembly is plugged (with carbon), you can clean it out yourself by removing the EGR valve & spray carb cleaner down the feed tube to clear it out. The carburetor cleaner & gunk will just blow into the exhaust manifold, so it's no biggie. The stuff will burn off when you run the engine. I think the dealer charges around $100 for this procedure. G/luck
Joel

I'm experiencing the same problem. I tried removing the EGR and spraying the tube out but it didn't look like it was that dirty at all. I have this truck sold and I'm banding my head off the wall. Isuzu won't cover doing the flush, which I don't think will work. They want $107 to do it. I'm running out of time to resolve this issue as the truck is heading out of state via internet sale. I've reset the ecm and keep getting the same code. I disconnested the tube at the exhaust, I might try spraying through again to see what happens. Any advice?

the problem you have is very common the problem is insufficient flow. When the EGR valve opens it allows ehaust gasses to recirculate through the engine. If the EGR vacuum port is restricted which it probably is, it will cause this concern.
HOW TO FIX
1 : remove the EGR valve
there are 2 holes the larger one is the one that supplies exhaust
flow dont worry about it. the other is a vacuum port this is
where exhaut gases are directed when the EGR valve opens carbon
carbon deposits srick to the walls of the vacuum port and in time
wil restrict flow normally about 30,000 miles
2: Check your local dealer for Intake cleaner ask about BG products
all you will need is the intake cleaner (spray can)
find something to plug the larger hole make sure it will not vibrate
and fall out there wil be slight exhaust pressure on it but not much
just be sure it is plugged real well because if not you may be
suprisied by a flame. Once plugged start the vehicle, spray intake
cleaner into the vacuum port you may have to raise the idle to do
or just open the throttle by hand spray untill the can is empty.
3 : check your EGR valve push the pintle on the bottom be sure it
moves in and out freely if not clean it dont replace the valve once
the pintle moves as it should reinstall the EGR valve disconnect
battery for a few minutes or have code cleared
I assure you if you do this it will take care of your problem I do this often sometimes 3-4 times a day and it always works

I have the same problem, my mechanic narrowed it down to the EGR solenoid being bad. I haven't had mine replaced yet, my mechanic assured me it could wait a while, and not cause other problems with the car.

2eyefishclaw what do you mean dont install once it moves[pintel].Are you saying you have to disconnect the battery first? When you say port are you talking about the brass line that goes to the manifold,or a port inside after you take the valve off?

clean the egr valve do not install a new one
vacuum port not exhaust
disconnect battery to clear trouble codes

Okay, so spraying down the vaccum port where the EGR sits, does it then go into the port that is located behind the trottle body? If not where does it go?

it will go into the intake but the reason for spraying it out as I suggested is to clean the port not the intake

I will have to change the gasket right?

when I pulled my EGR off the gasket came right with it and I was able to reuse it withour any problems.

Is there anyplace that has a diagram or photos that are clear of the egr ports and intakes where I should spray the cleaner to clean out the egr? I have a CEL and the stupid state won't inspect the car with that showing. Will disconnecting the battery for 30 mins make the codes go away?
thanks,
Kyle

http://kpaske.shacknet.nu/public/EGR.htm
http://www.geocities.com/endre_rl/isuzufaq.htm#faq1
http://www.icess.ucsb.edu/~greg/rodeo/egr.htm

I'll add the links to the FAQ soon ....

i took this advice about cleaning it out...and it worked perfectly. thanx so much. i would have still being trying to figure out what was wrong.

Is this the issue even if I feel some suction from the intake?

This would be awesome if this worked. my state requires emissions and I have had to delay renewing my registration b/c my emissions won't pass.

Thanks for any help

Thanks for posting this, I had the same problem and your post helped us out.



the problem you have is very common the problem is insufficient flow. When the EGR valve opens it allows ehaust gasses to recirculate through the engine. If the EGR vacuum port is restricted which it probably is, it will cause this concern.
HOW TO FIX
1 : remove the EGR valve
there are 2 holes the larger one is the one that supplies exhaust
flow dont worry about it. the other is a vacuum port this is
where exhaut gases are directed when the EGR valve opens carbon
carbon deposits srick to the walls of the vacuum port and in time
wil restrict flow normally about 30,000 miles
2: Check your local dealer for Intake cleaner ask about BG products
all you will need is the intake cleaner (spray can)
find something to plug the larger hole make sure it will not vibrate
and fall out there wil be slight exhaust pressure on it but not much
just be sure it is plugged real well because if not you may be
suprisied by a flame. Once plugged start the cars (http://www.dpccars.com/), spray intake
cleaner into the vacuum port you may have to raise the idle to do
or just open the throttle by hand spray untill the can is empty.
3 : check your EGR valve push the pintle on the bottom be sure it
moves in and out freely if not clean it dont replace the valve once
the pintle moves as it should reinstall the EGR valve disconnect
battery for a few minutes or have code cleared
I assure you if you do this it will take care tires (http://www.discountpartcenter.com/) of your problem I do this often sometimes 3-4 times a day and it always works

Can this problem also cause poor Mpg's? I recieve a P0401 code occasionally, but it usually goes away before I get to cleaning it. Then it comes back a month later. My Mpg's though, have dropped to 12-14. Could this be the problem?

I would like to Thank 2eyefishclaw for the entry here and others who tried it for their input. I know this is an old post but I just found my problem because of this post!! I took off my EGR valve and found that the pinion was locked up and very black. I tried to lube it as was suggested and it just would not free up. So, after replacing the part I have reset the CEL (Check Engine Light) and so far so good. I haven't given it a lot of time but I know that there was a problem with the fact that the pinion would not move. If you don't know how that part should work you don't know something is wrong with it. Thanks again and if you have this P0401 code check out your EGV valve and clean it as is suggested here! It's great information.