OBD Code P0404
#1
Racer
Thread Starter
OBD Code P0404
Hey Everyone,
I don't post often, but this is something I would like to share with my fellow Acura TL owners:
This morning, shortly after pulling into a client's driveway the engine began to idle roughly. I let it sit for a couple of hours then I went to start it again. It started but the idle was still rough. I drove it home and parked on hill. It had to be hill started (as in rolled down - another reason for a 6MT) as it would not start by cranking. I took it into the old garage where I used to work. My friend and I hooked up a SnapOn 2500 code reader to the ODBII port and discovered that failure code of P0404 (EGR Valve malfunction) had been recorded.
I removed the EGR valve and discovered that small pieces of carbon had logded the valve open, causing a lean idle condition. We cleaned out the carbon with compressed air and carburetor cleaner and ensured that the open-close action was smooth. We reinstalled the EGR valve and cleared the error code and she once again idled smoothly.
I hope this is of help to someone,
TL-Rocket
'04 TL 6MT 80,000 Miles
I don't post often, but this is something I would like to share with my fellow Acura TL owners:
This morning, shortly after pulling into a client's driveway the engine began to idle roughly. I let it sit for a couple of hours then I went to start it again. It started but the idle was still rough. I drove it home and parked on hill. It had to be hill started (as in rolled down - another reason for a 6MT) as it would not start by cranking. I took it into the old garage where I used to work. My friend and I hooked up a SnapOn 2500 code reader to the ODBII port and discovered that failure code of P0404 (EGR Valve malfunction) had been recorded.
I removed the EGR valve and discovered that small pieces of carbon had logded the valve open, causing a lean idle condition. We cleaned out the carbon with compressed air and carburetor cleaner and ensured that the open-close action was smooth. We reinstalled the EGR valve and cleared the error code and she once again idled smoothly.
I hope this is of help to someone,
TL-Rocket
'04 TL 6MT 80,000 Miles
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#5
Racer
Thread Starter
#6
I had the check engine light come on (acura TL 2004) after the low fuel light came on (coincidence or random?). Filled tank up and ensured the fuel cap was on tight (many clicks). Got the code check done and read P0404 (egr valve issue). Ran rough at idle. About 1 day later, with me doing nothing the check engine light went out...and idle smoothed out. Was this a fuel cap issue or is my egr valve about to die? Or did a piece of crud get stuck in the valve? Or what? Thanks for any insight.
#7
Racer
Thread Starter
I had the check engine light come on (acura TL 2004) after the low fuel light came on (coincidence or random?). Filled tank up and ensured the fuel cap was on tight (many clicks). Got the code check done and read P0404 (egr valve issue). Ran rough at idle. About 1 day later, with me doing nothing the check engine light went out...and idle smoothed out. Was this a fuel cap issue or is my egr valve about to die? Or did a piece of crud get stuck in the valve? Or what? Thanks for any insight.
Seems like a wild coincidence, but anything is possible.... You say that the fuel cap was replaced tightly before the P0404 code so I don't think the low fuel condition had anything to do with it; I've had the low fuel condition before almost every fill-up and this has never caused a CEL (P0404). When I had the P0404 code the car had been running roughly and eventually would not start (have 6MT so parked on hill as a precaution) using the starter motor - had to hill-jump start. Finally got it to my friends garage and determined the P0404 code. We waited for the engine to cool down and remove the EGR valve. The valve seat was caked in carbon deposits so I cleaned that out thoroughly and everything was fine.
In short if I were you I would remove the EGR valve and inspect and clean. You may have just gotten lucky in that the piece of carbon just lodged in a different area. The process to remove and clean is pretty straight forward.
In fact I'm going to inspect mine every 60K miles or so.
TL-Rocket
'04 TL 6MT
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dkerz (11-09-2012)
Trending Topics
#8
Jimmriley,
Seems like a wild coincidence, but anything is possible.... You say that the fuel cap was replaced tightly before the P0404 code so I don't think the low fuel condition had anything to do with it; I've had the low fuel condition before almost every fill-up and this has never caused a CEL (P0404). When I had the P0404 code the car had been running roughly and eventually would not start (have 6MT so parked on hill as a precaution) using the starter motor - had to hill-jump start. Finally got it to my friends garage and determined the P0404 code. We waited for the engine to cool down and remove the EGR valve. The valve seat was caked in carbon deposits so I cleaned that out thoroughly and everything was fine.
In short if I were you I would remove the EGR valve and inspect and clean. You may have just gotten lucky in that the piece of carbon just lodged in a different area. The process to remove and clean is pretty straight forward.
In fact I'm going to inspect mine every 60K miles or so.
TL-Rocket
'04 TL 6MT
Seems like a wild coincidence, but anything is possible.... You say that the fuel cap was replaced tightly before the P0404 code so I don't think the low fuel condition had anything to do with it; I've had the low fuel condition before almost every fill-up and this has never caused a CEL (P0404). When I had the P0404 code the car had been running roughly and eventually would not start (have 6MT so parked on hill as a precaution) using the starter motor - had to hill-jump start. Finally got it to my friends garage and determined the P0404 code. We waited for the engine to cool down and remove the EGR valve. The valve seat was caked in carbon deposits so I cleaned that out thoroughly and everything was fine.
In short if I were you I would remove the EGR valve and inspect and clean. You may have just gotten lucky in that the piece of carbon just lodged in a different area. The process to remove and clean is pretty straight forward.
In fact I'm going to inspect mine every 60K miles or so.
TL-Rocket
'04 TL 6MT
Do we need to remove the engine cover (Platic cover with Acura emblem) in order to get to the EGR valve?
Thanks
#9
Racer
Thread Starter
TL-Rocket
#10
Hey guys,
I kind of have the same issue too. I have an 05 TL automatic. Just recently it started to vibrate quite a bit when idle and when I looked at the rpm gauge the idle was very low around 500rpm or below. However, when I drive it, it drives fine. It also has problems starting up and won't start up unless I give it a bit of gas. the engine light was on so we connected it to a scanner and got the error codes of P0404 and P0401. Is this the kind of things you guys experienced too?
I kind of have the same issue too. I have an 05 TL automatic. Just recently it started to vibrate quite a bit when idle and when I looked at the rpm gauge the idle was very low around 500rpm or below. However, when I drive it, it drives fine. It also has problems starting up and won't start up unless I give it a bit of gas. the engine light was on so we connected it to a scanner and got the error codes of P0404 and P0401. Is this the kind of things you guys experienced too?
#11
Just resurrecting this thread to say I had the same problem. Was coming home yesterday from a long outing with my family. About two blocks from the house. I pull up to a stop light and the car is idling funny. Vibration and rpms hunting up & down. This morning we head out to church and it's still doing the same thing. Finally the CEL comes on. After church we head to the auto parts store for a quick code scan (and a lengthy explanation from the Autozone know-it-all ) resulting in a P0404. I go to start the car and it just won't fire up. Finally it barely catches and I'm able to keep it idling with the throttle. I get home and type "P0404 Acura Idle" into google and this thread is the #1 or 2 result.
After reading I pull my EGR valve and find a small 1mm chunk of carbon holding the valve open. I jam a plastic comb tooth into valve and pick the carbon out with a small flat-head. Remove the comb and the valve snaps shut. Mission accomplished. Thanks everyone. Now I just need to take a trip to a place where they let ME use the code reader so I can erase the codes myself.
Thanks again ACURAZINE!!!!
After reading I pull my EGR valve and find a small 1mm chunk of carbon holding the valve open. I jam a plastic comb tooth into valve and pick the carbon out with a small flat-head. Remove the comb and the valve snaps shut. Mission accomplished. Thanks everyone. Now I just need to take a trip to a place where they let ME use the code reader so I can erase the codes myself.
Thanks again ACURAZINE!!!!
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binhsterbinh (05-14-2014)
#13
IT's the small black canister looking thing pointed out in the lower left corner. Unplug it, remove two nuts at the base, pop the whole valve assembly off...
Once you take it off (small circular valve is to the left).
Once you take it off (small circular valve is to the left).
Last edited by 94eg!; 04-11-2012 at 02:20 PM.
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Mizouse (04-29-2017)
#16
Thank you guys for this post! I registered to AcuraZine forum to be able to reply to this post. I had the same problem with my car (2006 Acura TL). After a 400 km drive I stopped to pay a toll in US, and my car started to vibrate (idle funny) and RPMs were at about 500. Shortly after a check engine light appeared. It was driving normally and only start to idle funny when stopped. The next day I had to give it a bit of gas to start. The error code showed P0404. After reading this post I did exactly what you recommended - took the EGR Valve off and found a piece of carbon holding the valve open. Pulled it out, valve snapped back and the car runs perfectly again. Thank you very much!
#18
Burning Brakes
iTrader: (1)
Strange thing happened to mine 2 days ago. It was raining here in Chicago and the windows stated to fog up as I had the heat on at 75, so I turned the A/C on to get rid of the fog. When I came to a complete stop the RPM started going down to about 500 and then went back up to 800(normal idle). It did that 2-3 times and it looked like it was about to stall but it didn't. Drove it yesterday and today and no CEL yet. Runs a little rough at idle, the vibration is a little more than what it used to be at idle. Any idea- is it the EGR valve stuck open or....
#21
I know I am keeping the thread alive, but this just happen to my wife and I this morning. I happen to have an OBD2 scanner which has saved us a ton of money the last couple of years.
Came home and plugged it in to our 2005 Acura TL and got the P0404 which lead me to this thread after a quick search. Fixed the car in a very very short about of time! Had two decent size chunks of gunk that keep the little valve open. Cleaned everything out and started the car........ ran smooth once again. Crazy how something so small can make your car/engine feel like its about to die!
Great thread and I hope more people see it if this problem comes to light!
Thanks everyone!
Came home and plugged it in to our 2005 Acura TL and got the P0404 which lead me to this thread after a quick search. Fixed the car in a very very short about of time! Had two decent size chunks of gunk that keep the little valve open. Cleaned everything out and started the car........ ran smooth once again. Crazy how something so small can make your car/engine feel like its about to die!
Great thread and I hope more people see it if this problem comes to light!
Thanks everyone!
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shamal (12-29-2014)
#27
Same happened to me a few weeks back. Honestly thought my transmission was done. Luckily it threw the code and it was fixed. This happened after i "floored" it on the Southern State Parkway ramp (cause those entrances are just too short and no one gives you a chance to get on). Piece of carbon was stuck in the valve holding it open
#30
Just wanted to say thanks to the OP.
I had this happen to me today after getting off the interstate. I am in WY for training and am leaving tomorrow to head back home (10 hour drive).
Thankfully there was a home depot across the street from my hotel so I purchased a 12mm wrench (this is the LAST time I leave home with out a small tool kit in the car) and pulled the EGR valve.
Ended up finding a small round chunck of carbon holding the valve open. Removed it using my gerber tweezers and re-installed the valve.
i had no check eng light but i did have the P0404 code pending so I cleared that using my Torque andriod app (you need a OBD2 bluetooth adapter to use Torque).
Runs like a champ once again. Thanks Guys!
I had this happen to me today after getting off the interstate. I am in WY for training and am leaving tomorrow to head back home (10 hour drive).
Thankfully there was a home depot across the street from my hotel so I purchased a 12mm wrench (this is the LAST time I leave home with out a small tool kit in the car) and pulled the EGR valve.
Ended up finding a small round chunck of carbon holding the valve open. Removed it using my gerber tweezers and re-installed the valve.
i had no check eng light but i did have the P0404 code pending so I cleared that using my Torque andriod app (you need a OBD2 bluetooth adapter to use Torque).
Runs like a champ once again. Thanks Guys!
#31
Smoke
I have a 2006 RL with the P0404 error and am going to check the EGR valve when the engine cools down. I have also seen quite a bit of blue smoke when I start the car. Do you think it might be related to that error?
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Scottwax (04-27-2015)
#34
This thread should never dies
I had the same problem yesterday and fixed it today with a bit of google research and this thread, which pinpoint to the exact problem. I was worrying my car engine was dying that's why it idled roughly.
#35
Moderator
Join Date: Oct 2004
Location: Not Las Vegas (SF Bay Area)
Age: 40
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2007 TL here. Just had this issue and code pop up for me today on my way from my house (east SF Bay Area) to Davenport/Santa Cruz, CA.
same symptoms, rough idle and car shaking, hovered between 800 and 500rpm. When the car is in drive and I'm at a stop and try to start moving, the RPMs drop way low and if I don't give it a lot of gas, the car will stall.
luckily I was able to get the car home (wasted like 3hrs of my time )
weird thing is the issue is gone right now. Car is driving fine.
Anyways, gonna give the cleaning of the EGR valve a try tomorrow AM.
same symptoms, rough idle and car shaking, hovered between 800 and 500rpm. When the car is in drive and I'm at a stop and try to start moving, the RPMs drop way low and if I don't give it a lot of gas, the car will stall.
luckily I was able to get the car home (wasted like 3hrs of my time )
weird thing is the issue is gone right now. Car is driving fine.
Anyways, gonna give the cleaning of the EGR valve a try tomorrow AM.
Last edited by Mizouse; 04-29-2017 at 10:52 PM.
#36
Thank you!
Stuck valve
2007 TL. Literally same issue as everyone. Carbon "Rock" keeping valve open.
Used this video to help me understand how to take the valve off. 5 minutes of work.
https://m.youtube.com/watch?v=q_weetqqx1c
2007 TL. Literally same issue as everyone. Carbon "Rock" keeping valve open.
Used this video to help me understand how to take the valve off. 5 minutes of work.
https://m.youtube.com/watch?v=q_weetqqx1c
#37
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Join Date: Oct 2004
Location: Not Las Vegas (SF Bay Area)
Age: 40
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One other piece of advice I'd give is to give your car a quick "Italian tuneup" basically run your car between 4-5k RPM with the occasional redline for 10-15 minutes.
this will help remove carbon build up due to increased pressure.
i inadvertly did this on my drive home cause I was keeping the RPMs Around 4k to prevent my car from stalling out.
when I got home. My car was working fine. No symptoms of any issues were showing. When I checked my EGR valve, there was nothing blocking it.
anyways I sprayed it with some carbon cleaner and gave it another "Italian tuneup"
heres a pic of my EGR valve when I took it out and after spraying it with carbon cleaner
this will help remove carbon build up due to increased pressure.
i inadvertly did this on my drive home cause I was keeping the RPMs Around 4k to prevent my car from stalling out.
when I got home. My car was working fine. No symptoms of any issues were showing. When I checked my EGR valve, there was nothing blocking it.
anyways I sprayed it with some carbon cleaner and gave it another "Italian tuneup"
heres a pic of my EGR valve when I took it out and after spraying it with carbon cleaner
Last edited by Mizouse; 05-15-2017 at 07:08 PM.
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Slpr04UA6 (05-16-2017)
#38
I have replaced EGR valve and my OBD fails to clear code P0404 when attempting to clear. P0404 also appears twice on OBD meter. Does anyone know if I have more issue with the vehicle? Why does my Innova 3030 OBD2 fail when attempting to clear code?
#39
Senior Moderator
Try just unplugging the battery for a few minutes to see if it will reset.
#40
Never did unplug battery to reset. But my wife drives the Acura and said the engine light turned off on its own on the third day after replacing EGR valve.
I still Thank you for your suggestion
I still Thank you for your suggestion