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Discussion Starter · #1 · (Edited)
2 days ago my vehicle was running perfectly (AFAIK)
Had serious rainfall in the nightime, yesterday morning when leaving for work, I started the vehicle, felt a shaking while i idle, after 60 seconds i turned off the vehicle.
There were no CEL showing,
Started the vehicle again, still shaking, after about 1 mile on my route, the VTM-4 and the CEL Light appeared, when I slowed to stop at lights, the vehicle had a rough vibration/shaking, when i pressed on the gas to accelerate/go , there were minor "hi-cups" felt, as if the vehicle was about to stall.
Got to my destination, insert my OBD2 scanner, got a P0404 code.
When I got home, connected my Laptop to my OBD2 in the vehicle with ScanMaster Program and got the P0404 code again.

Watched some YouTube videos about P0404 and I am/was about to perform/see if cleaning, or replacing the EGR valve and/or gasket would solve the issue.

But I was unable to get loose the two 12mm bolts.
Stopped by a mechanic to see if they could JUST loosen the bolts for me, one refused, second was unable to get the bolt loose, I told him use at least a torgue wrench, or power tool, but he insisted on using his strength , he failed
I have sprayed some WD40 on the bolt, still couldn't get the bolt loose, 30 minutes later sprayed again WD40 , still not able to get it loose, Sprayed AutoZone Penetrant Oil, waited to dry, still can't get the bolts loose.


EGRlocation.jpg


EGRvalve&Bolts.jpg




Today, a day after the problem started, the vehicle started with no vibrations, the VTM-4 light is OFF, but the CEL remains.

I need to find a way to get the bolts loose, so I can clean/replace the EGR myself, the EGR is about $80 at Autozone ( www.autozone.com ), gasket about $2.50

I don't need to pay a mechanic $60 labor to do a 5 minute job that I can do myself.
I just need the bolts loosen


............................................................................................................


P0404 Trouble Code: Exhaust Gas Recirculation EGR

P0404 code definition

P0404 OBD-II Trouble Code: Exhaust Gas Recirculation Circuit Range/Performance

Exhaust Gas Recirculation Circuit Range/Performance
What the P0404 code means

P0404 is an OBD-II generic code that the engine control module (ECM) detected the engine exhaust gas recirculation (EGR) valve or sensor is out of specification range or its performance has gone out of specification parameters.
What causes the P0404 code?

  • The ECM monitors the EGR position with a sensor mounted on top of the EGR valve and the valve was out of a set position when the EGR was commanded closed.
  • The EGR valve movement should be smooth without jerking or the ECM sets the code.
  • The EGR sensor went above upper limits when the EGR was commanded open by the ECM.
What are the symptoms of the P0404 code?

  • The Check Engine Light will be illuminated and the code is set in ECM memory.
  • The engine may have pre-ignition on acceleration.
  • The engine EGR system can cause the engine to run rough, hesitate or even stall if it is not indicating the proper EGR valve position to the ECM.
How does a mechanic diagnose the P0404 code?

  • Scans codes and documents the freeze frame data in order to verify the problem
  • Clears the engine codes and road tests to verify if the concern comes back
  • Monitors the EGR sensor pid on a scanner to see if sensor indicates the valve is stuck open or not moving smoothly
  • Removes the EGR sensor and manually operate the sensor to isolate a valve or sensor failure
  • Removes and checks the EGR valve to verify it is not carboned up, causing the bad sensor readings.
Common mistakes when diagnosing the P0404 code

  • Not operating the EGR position sensor manually to isolate a valve or sensor failure before replacing components
  • Not checking the wiring harness and connection to the EGR position sensor for problems before replacing the EGR position sensor or EGR valve
How serious is the P0404 code?

  • An EGR system that triggers this code the ECM may disable the EGR system and render it inoperative.
  • The Check Engine Light being on causes the vehicle to fail emission testing.
  • The EGR position is critical for the ECM to properly control EGR valve opening and closing.
What repairs can fix the P0404 code?

  • Replacing the EGR valve if it stuck partly open from carbon buildup in the pintle area and cannot be cleaned.
  • Replacing the EGR position sensor if it is determined that it cannot give a correct input reading to the ECM when moved manually
  • Repairing the wiring that is shorted or open to the EGR position sensor or connector
Additional comments for consideration regarding the P0404 code

Code P0404 is triggered when the EGR position is not as the ECM expected and the most common cause is the EGR valve partly stuck open from carbon buildup on the valve pintle.






egr egr egr valve location egr valve cleaning p0404 carbon cleaning egr valve gasket egr gasket
diagnostic trouble code (DTC)
 

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Use something like PBBlaster ..dont use WD 40 ... i PB blast that wait a few minutes and they come loose.
 
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2 days ago my vehicle was running perfectly (AFAIK)
Had serious rainfall in the nightime, yesterday morning when leaving for work, I started the vehicle, felt a shaking while i idle, after 60 seconds i turned off the vehicle.
There were no CEL showing,
Started the vehicle again, still shaking, after about 1 mile on my route, the VTM-4 and the CEL Light appeared, when I slowed to stop at lights, the vehicle had a rough vibration/shaking, when i pressed on the gas to accelerate/go , there were minor "hi-cups" felt, as if the vehicle was about to stall.
Got to my destination, insert my OBD2 scanner, got a P0404 code.
When I got home, connected my Laptop to my OBD2 in the vehicle with ScanMaster Program and got the P0404 code again.

Watched some YouTube videos about P0404 and I am/was about to perform/see if cleaning, or replacing the EGR valve and/or gasket would solve the issue.

But I was unable to get loose the two 12mm bolts.
Stopped by a mechanic to see if they could JUST loosen the bolts for me, one refused, second was unable to get the bolt loose, I told him use at least a torgue wrench, or power tool, but he insisted on using his strength , he failed
I have sprayed some WD40 on the bolt, still couldn't get the bolt loose, 30 minutes later sprayed again WD40 , still not able to get it loose, Sprayed AutoZone Penetrant Oil, waited to dry, still can't get the bolts loose.


View attachment 139155

View attachment 139156



Today, a day after the problem started, the vehicle started with no vibrations, the VTM-4 light is OFF, but the CEL remains.

I need to find a way to get the bolts loose, so I can clean/replace the EGR myself, the EGR is about $80 at Autozone ( www.autozone.com ), gasket about $2.50

I don't need to pay a mechanic $60 labor to do a 5 minute job that I can do myself.
I just need the bolts loosen


............................................................................................................


P0404 Trouble Code: Exhaust Gas Recirculation EGR

P0404 code definition

P0404 OBD-II Trouble Code: Exhaust Gas Recirculation Circuit Range/Performance

Exhaust Gas Recirculation Circuit Range/Performance
What the P0404 code means

P0404 is an OBD-II generic code that the engine control module (ECM) detected the engine exhaust gas recirculation (EGR) valve or sensor is out of specification range or its performance has gone out of specification parameters.
What causes the P0404 code?

  • The ECM monitors the EGR position with a sensor mounted on top of the EGR valve and the valve was out of a set position when the EGR was commanded closed.
  • The EGR valve movement should be smooth without jerking or the ECM sets the code.
  • The EGR sensor went above upper limits when the EGR was commanded open by the ECM.
What are the symptoms of the P0404 code?

  • The Check Engine Light will be illuminated and the code is set in ECM memory.
  • The engine may have pre-ignition on acceleration.
  • The engine EGR system can cause the engine to run rough, hesitate or even stall if it is not indicating the proper EGR valve position to the ECM.
How does a mechanic diagnose the P0404 code?

  • Scans codes and documents the freeze frame data in order to verify the problem
  • Clears the engine codes and road tests to verify if the concern comes back
  • Monitors the EGR sensor pid on a scanner to see if sensor indicates the valve is stuck open or not moving smoothly
  • Removes the EGR sensor and manually operate the sensor to isolate a valve or sensor failure
  • Removes and checks the EGR valve to verify it is not carboned up, causing the bad sensor readings.
Common mistakes when diagnosing the P0404 code

  • Not operating the EGR position sensor manually to isolate a valve or sensor failure before replacing components
  • Not checking the wiring harness and connection to the EGR position sensor for problems before replacing the EGR position sensor or EGR valve
How serious is the P0404 code?

  • An EGR system that triggers this code the ECM may disable the EGR system and render it inoperative.
  • The Check Engine Light being on causes the vehicle to fail emission testing.
  • The EGR position is critical for the ECM to properly control EGR valve opening and closing.
What repairs can fix the P0404 code?

  • Replacing the EGR valve if it stuck partly open from carbon buildup in the pintle area and cannot be cleaned.
  • Replacing the EGR position sensor if it is determined that it cannot give a correct input reading to the ECM when moved manually
  • Repairing the wiring that is shorted or open to the EGR position sensor or connector
Additional comments for consideration regarding the P0404 code

Code P0404 is triggered when the EGR position is not as the ECM expected and the most common cause is the EGR valve partly stuck open from carbon buildup on the valve pintle.






egr egr egr valve location egr valve cleaning p0404 carbon cleaning egr valve gasket egr gasket
diagnostic trouble code (DTC)
As @Tahoefever said, PB Blaster is good stuff. I've had great success with brake fluid over the years. Just a 2-3 drops on each. Maybe twice, 3 times if really bad.
 
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Discussion Starter · #4 ·
i tapped the bolt a few time with a hammer, hoping to shake loose...
Started the vehicle after I wasn't able to loosen the bolt, there were no more shaking, also, the CEL is no longer showing

Drove about 15 miles since, everything is running normal .

I'm about to pick up some PBblaster still, need to get those nut and bolt free to inspect

Thanks Piloteers, will follow up on this.
 

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Righty righty, lefty loosely? Just making sure you’re turning the wrench the correct way.😁

I used some TriFlow Superior lubricant on those two bolts and let it sit overnight. They came right off the following morning.
 
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Righty righty, lefty loosely? Just making sure you’re turning the wrench the correct way.😁

I used some TriFlow Superior lubricant on those two bolts and let it sit overnight. They came right off the following morning.
Sounds like a joke, but this is actually some great obvious advice. Always easy to overlook the basics!
 

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Discussion Starter · #7 ·
PBBlaster was NOT successful.. after *4 tries... can is almost empty..

No stores seem to have SeaFoam around here, might have to order online/ebay

*PBBlaster
spray - wait 30 minutes - X
spray - wait 1 hour - X
spray - waited 3 hours - X
spray - waited ~ 9 hours = overnight - X
X = no success.

Vehicle is still working fine. maybe the hammering on the bolt knocked loose carbons that was built up in the EGR Valve and cleared the passage a bit...
 

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Maybe the previous owner used Loctite Red on those nuts. They are small and don’t require much torque to tighten. That is crazy that you can’t get them loosened.
 

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Yeah, I don't know what gives,
even a mechanic tried, and couldn't get them off.....
Heating the bolts would be ideal. Maybe can rent an induction heater to heat the bolts, they seem to work wonders when all else fails.
 
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