If something triggers the CEL and then after so many miles the ECU doesn't see the issue anymore, in some instances the ECU will turn off the CEL but 'save' the P code in memory. To clear the codes you either need to 'Clear DTC's' with Evoscan (bottom right corner of screen), go to your local Autozone or Advance Auto Parts store and have them clear them for free or disconnect the car battery for 5 minutes or so. This will wipe the slate clean. If you get a code again, you'll know its something recent thats an issue that needs attention.

 

thanks jack good info i pulled the batt cable yesturday after it came back on....and it is off now but maybe ill go back to autozone and have them clear it with their scanner...thanks again...you dont know anything about hids do you lol....
https://www.evolutionm.net/forums/ev...blem-help.html

 

I've been chasing a power loss of rougly 10whp/10torque since early in this year. I fixed some pretty big boost leaks, evaluated motor oil analysis, retuned over and over, increased boost, and still was never able to hit my old power levels, UNTIL NOW!

My car threw the P0401 today, so I used EvoScan to read it, then researched it up and landed on this thread. Sure enough, just like everyone else, one of my hoses was just dangling. I reconnected it and took it out for a couple logs, and now my power is right back up to where it used to be! Thanks EvoM!

 

I disabled my P0300 last friday and was clear of codes. I drove for about 20 miles and parked the car in the garage code free. My wife took the car out the next day and calls me saying..."I thought you cleared the CEL, did you disconnect the battery?" Being that I was 200 miles away I couldn't do anything about the car. So, I took it up to the Advanced Auto Parts up the road to get the codes pulled. I had:

P0401
P0011
P0442

I went out and checked the car after it had a chance to cool down and sure enough one of the vacume lines from the egr had come off. I put it back on and zip tied both EGR lines to the EGR. Sidenote: since my battery is relocated to the trunk I could see the EGR after popping the hood. Perhaps later I can snap a pic and post it in the thread since I read earlier how people were having trouble locating the EGR and lines.

Afterwards I checked the gas cap for the P0442 code and then disconnected the battery for a few minutes to reset the ecu. I'm also going to check the sensor for the cam, but I'll need more time than I have available right now to look into that one.

Thanks to those who figured this out before me and posted up the common source of the code. It makes things much easier when this type of resource is available.

 

Awsome!!!!! Got my hands on a actron and read p0401 found this thread and it was an easy fix.........swwwwwwwwwwwwweeeet and thanks!!!!

 

This is the second time I have used this thread to help get rid of the P0401 code. The hose on the nipple pointing toward the passenger tire had blown off. Stick it back on, clear the code, good as new.

 

that was my 401 error code as well this site is better that ANY of the other sites.
I love evolutionM.....

 

Problem solved thanks to this thread. Kudos

 

Same problem, a sneaky hidden hose dangling from EGR... Fixed!

 

For those of you who had an EGR hose pop off, fixed it, reset the ecu by using the battery method...how long before your car was back to normal?

I've put about 50miles (5-6 start-ups) on the car. Vacuum is normal, idle afr is normal but WOT afr is about a full point rich. In 3rd gear I'd spike at about 11.7 and would taper to low 11s by 7k. Now I see a spike of 10.9 or so and afr will raise to low 11s at 7k. Did a boost leak test today and everything is ok. Checked those EGR lines sooo many times too just to make sure. CEL has not returned.

Give it more time? Car drives fine, pulls ok, boost is the same as before. I was just tuned 2wks ago w/ a new FP green, so I can tell I'm down a little power. I've only had the wideband installed for about a year, and hadn't reset the ecu in that time, until now...so I can't say if its normal to run rich after disconnecting battery to clear a code. Thanks...amazing this thread has been active since 2004

 

Great, another person with the code (Me)... I just checked for any loose hoses now and I don't have a loose hose. Both are connected to EGR solenoid. Just hit 99k on and 03. Minimal mods: Intake, TBE, Exhaust mani, 9 turbo and titek o2 housing. I thought it was just my test pipe that was giving a cel but since I was going to smog soon, I double checked and got a p0401 along with it... I am still currently searching for answers. Thanks guys.

I just checked the passenger side of the hoses where the sensor is and found that the white hose broke off a dawn nipple.

 

Dealing with this issue right now.

 

still dealing with this issue

 

^ Same here my friend and I don't have any hoses that aren't connected. Would the car throw this code if the cat were gutted?

 

I've been driving around with this for 8 months!! I thought it was the normal misfire code until I finally checked it....and thanks to evom...I found my hose from the EGR valve hanging. thx all!!