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Tkavil
1997 Camry LE
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26 Posts
Discussion Starter · #1 ·
I've been noticing more recently that on cold starts, my Camry releases a significant amount of white/grey smoke from the exhaust which lasts 5 seconds or so? Should I be concerned? At the moment I have CEL P0401, I've cleaned Valve and replaced the modulator. Is the smoke possibly related?
 

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Moderator
1998 T100 SR5 2WD
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14,849 Posts
http://www.obd-codes.com/p0401
P0401 OBD-II Trouble Code

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Technical Description

Insufficient EGR Flow
What does that mean?

EGR stands for Exhaust Gas Recirculation. It is part of the vehicle emmissions system, and is used to reduce combustion temperature and pressure to control Oxides of Nitrogen. There are generally three parts to the EGR system: the EGR valve, an actuator solenoid, and a differential pressure sensor EGR (DPFE). These things work together to deliver the correct amount of recirculation based on engine temperature, load, etc. The P0401 code means that OBD detected an insufficient amount of EGR.
Symptoms

You may notice drivability problems such as pinging (a.k.a. pre-ignition knock) when the engine is under load or the vehicle is at higher speeds. There may also be other symptoms.
Causes

A code P0401 most likely means one or more of the following has happened:

  • The DPFE (differential pressure feedback EGR) sensor is faulty and needs to be replaced
  • There is a blockage in the EGR (tube), most likely carbon buildup
  • The EGR valve is faulty
  • The EGR valve may not be opening due to a lack of vaccuum
Possible Solutions

In fixing this code, it is quite common for people to just replace the EGR valve only to have the OBD code return. The EGR valve is not always the culprit.

  • Use a vacuum pump and pull the EGR valve open while monitoring engine RPM's & DPFE voltage. There should be a noticable difference in RPM's with the EGR open
  • Clean out the EGR valve and/or tubing to remove deposits
  • Check the voltage at the DPFE, compare to specified values (refer to a repair manual for your specific model)
  • Replace the DPFE sensor (with a good quality / OEM one)
  • Replace the EGR valve
Related EGR Articles: P0400 - P0402 - P0403 - EGR System Explained

*****
Pull the spark plugs and snap some piccies of the business end. Post them up here in the thread... ;)

If you have a cylinder or more burning coolant, the spark plug(s) and piston(s) will be cleaner than the other ones. If that's the case...most likely a head gasket.

Was any other maintenance performed before this condition? The code yer pulling shouldn't have anything to do with the coolant in the exhaust... ;)
 

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Tkavil
1997 Camry LE
Joined
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26 Posts
Discussion Starter · #5 · (Edited)
A while ago when I was looking at my EGR Solenoid I noticed the parts around my engine were oily. I was unable to source the leak and kind of shrugged it off. How can I confirm that it is the intake manifold?

Here are some pictures I took..









It appears to be at the very far right (Driver's side) coming out of the intake possibly? I don't know how this is reaching my exhaust though?
 

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2,101 Posts
boy howdy that looks WEATHERED! Likely a valve cover gasket leak as those big nuts on the spark plug tubes loosen frequently. White smoke means antifreeze in exhaust, classic sign of weepy head gasket. Oil burns bluish black, valve cover leak is unrelated.

My 94 had similar symptoms and finally blew head gasket and I pulled head and replaced head gasket along with all seals and timing belt H2O pump. Runs great now.

Oh and EGR valve was near plugged so I scraped out C buildup.
 

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Tkavil
1997 Camry LE
Joined
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26 Posts
Discussion Starter · #7 ·
boy howdy that looks WEATHERED! Likely a valve cover gasket leak as those big nuts on the spark plug tubes loosen frequently. White smoke means antifreeze in exhaust, classic sign of weepy head gasket. Oil burns bluish black, valve cover leak is unrelated.

My 94 had similar symptoms and finally blew head gasket and I pulled head and replaced head gasket along with all seals and timing belt H2O pump. Runs great now.

Oh and EGR valve was near plugged so I scraped out C buildup.
Replacing the Valve cover gasket and Head gasket, how would you rate it's difficulty from 1-5 beers?
 

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2,101 Posts
valve cover is EZ, headgasket much less so, as you need to pull head and its a pain. That said I did it in a parking lot with intermittent rain storms and minimal equipment but it took me several days. Manuals describe process very fully, garage wanted $1500-2500 and it cost me <$600. If you have a dry well lit garage, decent tools and a second car you can do it in a day. Real pain is reconnecting all the crap on the back of the engine as some of those require good bottom access, which I didn't have, also tiny hands would help ;) Oh $600 included rental car for multiple days to run head to machine shop for surfacing and visit Napa for stuff I forgot!
 
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