2002 4 Cyl Toyota Camry P0401 Insufficent EGR Flow Code

T

ttrah

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#16
I also put Seafoam gas system cleaner in today...
 
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#18
ttrah...I have probably spent an hour looking for info about a EGR temp sensor for that car but I'm only finding that sensor with the V6. But if you have one, and the PCM is using it to determine adequate flow, you need to test it for accuracy.
 

billr

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#19
By '01 were emissions equipment the same in all states, or could this be a car with "special" stuff, like for Calif?
 
T

ttrah

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#20
Thanks again for all your support!!!

I finally went through the vaccuum test proceedure and everything checks out. Something to throw out there, when I had the throttle body off, I noticed liquid ( probably water) in the bottom rear larger hose. Just struck me as odd because it was attached to the throttle body. I assume it has something to do with the evap system leading to the canister so I didn't pay much attention to it.

What if the problem is steming from the canister hoses/ VSV's? The drawing show a VSV for the evap, one for the pressure switching valve and one for the canister. Is it possible to get this code P0401 if there was a problem with any of these?

One other thing, I noticed a oily water mix dripping on the driveway from under the car behind the driver's seat from a slotted plastic/aluminum panel where the canister hoses run with the brake lines. This just started so I am puzzeled. If I wipe up the stain on the driveway, it is orange and smells like oil.

I've thrown about $550 at this issue and soooooo many man hours without resolution. I gotta be close but I gotta get it resolved soon ..... Any further input is welcomed. Thanks
 
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#21
The hose you mention at the t-body probably has coolant running through it. Any chance you mixed up some hoses and coolant is getting into the evap system? Scary thought...
 
T

ttrah

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#22
Hi Dan, 100% sure the hoses went back on the way they came off. It didn't look like coolant just plain water.
 
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#23
I never was so teed off in my life when all I could put in my 88 Supra was ethanol gas, had to redo the entire fuel system. Only sign by the gas cap cover was do not use leaded gas, like you could even buy leaded gas in 1988. Ethanol must have been around back then because my 1986 boat has a big sign by the gas cap, do not use ethanol.

So whats the story on your 2001?

With a rough running engine, first step for me is to do a compression test just to get this out of the way, then the ignition using a spark gap tester on each cylinder, if applicable, ignition timing, then check for vacuum leaks, fuel system comes last.

In particular with EGR problems, if compression is low, verify this with a cylinder leak down test. Then flip a coin to determine whether the vehicle is worth repairing or not. On heads that I have pulled either a crack in the head or nothing left of an exhaust valve seat. But don't go this far, even before throwing a cent at it. Son's 2000 Taurus was this way with a cylinder down to zero with 256K on it, and a DOHC engine at that. Just drove it to the wrecking yard and got 300 bucks for it.
 
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ttrah

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#24
Hi Nick, the car runs great without the EGR valve connected. The engine runs rough because I believe for some reason. too much exhaust gas is being introduced to the intake. Crazy thing is, the code is a P0401 and P0402. It's like the computer can't read the correct values. Everything to do with the EGR valve has been replaced and or cleaned. The mystery fluid was an unrelated brake line leak.
 
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#25
Are you pulling off the vacuum hose off the EGR to test it for complete closing or removing it and blocking the passage? Former tells you the EGR is okay, a final test is opening it with hand operated vacuum pump that should kill the engine. Could have vacuum control problems.

a 42 year old problem, using a fuel that would burn up any internal combustion engine with some type of injecting old exhaust fumes into the engine to cool the combustion chamber temperature. Was some talk about using ceramics that can take the heat, but never done.

A far more reliable system is to close the exhaust valves early leaving burnt exhaust gases in the combustion chamber in proportional amounts. If that cheap vacuum line falls off, will burn up your engine. Using lead in fuels was also not a good idea, drives people nuts and aggressive so they run for congress.

But in the last 42 years, nothing was done to solve this age old problem trying to develop a fuel that does not burn up an IC engine. But auto makers like it and by jacking up the prices for parts, gives you a reason to buy a new car.
 
T

ttrah

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#26
Right now I have the vacuum line pulled off the EGR valve and it runs fantastc. I have replaced the EGR valve, solinoid and regulator already. If I take a vacuum pump and pull in the EGR valve, car stalls immediately.
My problem is that it will not pass the emission test next year so I will not be able to keep it registered. I have thrown a ton of time and $$$ at this trying to avoid the dealer. I may have to bite the bullett and see what they have to say. The car has 121K on it so is there anything else that might be a problem? This car gets 25 MPG religiously with the EGR valve disconnected.
 
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#27
ttrah, you wrote..."4-I removed the throttle body and cleaned it like it was brand new. All ports looked clean and passed cleaning fluid without issue. I removed the temp sensor in the exhaust manifold and hit that with carb cleaner as well."

Is that a temp sensor in the part of the Exhaust manifold that would get hotter if the EGR was open and letting exhaust flow past the sensor? A ECU could use a sensor like that to determine proper EGR function. Tell me more about that sensor that you hit with carb cleaner.
 
T

ttrah

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#28
Here are 2 links. The sensor I removed and cleaned was right in front of the motor screwed into the exhaust manifold. The other link says that there is a 2nd after the catalytic converter. Would I get a different code if the catalytic converter was clogged?

https://search.yahoo.com/search?p=picture+of+2001+camry+exhaust+sensor&fr=yfp-t-450

http://www.answers.com/Q/Where_is_the_oxygen_sensor_located_on_a_2001_Toyota_Camry
 
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#29
Hmm...well...I guess you fooled me when you called the oxygen sensor (or more accurately, Air / Fuel Ratio sensor, if it's the "upstream" one) a temp sensor.

Hey, check out this link, especially the part about what can happen if you get the hoses switched into the wrong positions... http://www.toyotanation.com/forum/103-3rd-4th-generation-1992-1996-1997-2001/304896-p401-insufficient-egr-flow-detected-1999-camry-4cyl-2.html
 

nickb2

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#30
I cannot of me find for the life of me an EGR on board a 2002 2AZ-FE camry. Or any camry with a 4 banger from 2001 to 2004. I am confused. The vacuum diagram that old man shows, does show EGR. Is this california only?? Was that vacuum diagram from old man a 2.4l 2AZ-FE? I am still confused. Normally the old man is on the ball.

The only thing that I find EGR related is on the 5S-fe engine in 2000. They call it the VSV for EGR. No such thing on my Alldata base for 2002.

I cannot find a P0401-402 code chart either. Damned if I know whats going on here.

Anybody else, feel free to chime in cuz I have checked everywhere, and ALL SITES and parts stores say the egr was eliminated with the 2.4l. On the 2002 2.4l camry, the VSV goes straight to the evap canistor. Maybe the canister is in trouble.

At this point I am blowing smoke out of my arse cuz I feel I don't have proper info to help any further.
It would still not post a P0401/402 unless it is a manufacturer code, and I still can't find that one either.

So this is me (|0|) :giveup |??