EGR codes and my quest to defeat them .... (1 Viewer)

Joined
Jan 19, 2009
Messages
7
Location
omaha, ne
I am new to this site and this is my first post. Before I get started, I want to point out that I am not a mechanic or a rocket scientist or a grammer/ spelling teacher. I have a general idea of how things work, but don't always know....... Most all that I have done to figure out what I have, is due to reading posts here, and my own observations.

I got the dreaded egr insuf. flow code...PO401... After finding out what the parts to the egr system cost, I figured that I would try and "fix" what I could.... I ordered the egr seal for only a couple bucks..... removed the egr valve itself and cleaned it the best I could and soaked it in carbon remover cleaner. tested by moving the piston up and down with a pair of needle nose pliars.... sucked on the vacumm line to check the diaphram . It seemed all ok and worked the way i thought it should. Next I started up the truck and checked the flow of exaust out of the tube that comes up..... seemed like it was clear of any clogs...... after deciding that it all seemed ok I put it all back together. unscrewed the temp sensor and cleaned the carbon off it and reinstalled it.... put it all back together, disconnected the battery to clear the code and started it up. drove for a day and got the code po401 again. Took it to Advanced Auto for the free code read........
after Reading meny threads on this site, I decided that i needed to check out the Vacumm Switching Valve ... or VSV. but I was a little intimidated by the process.... but after a few days of trying to come up with a plan I just decided to go with the removal of the throttle body ... I was actually suprised that it was really easy. I took some digital pics of it all together just in case..... it only took about 20 to 30 minutes to get to the vsv and remove it.... the air cleaner "tube", a few vacumm hoses, 2 small coolent hoses, 4 bolts and vvvvwala........

I had read one thread discussing moving the VSV to another place in the engine compartment . not only to provide easier acsess, but for cooler operating temp too.... thought it seems like a good idea, so I threaded the electrical wire through to where i could get to it later... ran longer vacumm hoses for the same reason.....

I tested the VSV the only way it made sence to me..... sucked on one hose and ran 12 volts across it and it didnt close..... COULD THI BE MY PROBLEM? well after coming to the conclusion that it was bad, i figured that i would take it apart to see if I could get it to work... hey, maybe it was just a little piece of carbon blocking it..... I was very suprised as to how simple this thing is.... a basic sylanoid..... an electromagnet with a rubber stopper on the end..... it was stuck in the open position.... I started thinking....

If it is stuck in the open position, air is constantly going through it....... not allowing enough sucktion to pull up the diaphram on the egr valve to open it.... SO, I pluged the hoses that came off the VSV so that it would duplicate the valve being stuck closed......... this in theory , would make the egr valve open almost all the time........ WOULD I GET THE OPPOSITE CODE THAN I WAS GETTING BEFORE? Ecsessive flow? PO402?

Three days later I got my answer.......

My check engine light came on..... ironicly 1 block away from Advanced Auto..... stopped in and in 5 minutes found out that this time I had too much air flow....... The opposite of my origional code and problem ...... I think I found my problem....

NOW.... my next question..... since I am relocating the VSV, why couldnt I use one from a different vehicle that is much less expensive? as long as it is "open" when there is no voltage , and closed when there is..........

Has anyone ever done this? I just don't have the money for the Toyota one right now....

I did get a 1k ohm resistor to fool the ecu for now.

also, I did bump the timing up to 9 deg. BTDC ...... this is a wonderful suggestion....and makes a huge differance.... thanks guys.....
 

Proven

RTFM, STEP 6, POST
Joined
Apr 11, 2006
Messages
912
Location
Atlanta
 
 
I have to say that was a very difficult post to read. Punctuation shouldn't be used that much, even for effect.

Now, I wouldn't recommend by-passing anything that MR. T put into the system. The code really has little effect on performance, it is really more of an annoyance actually. If you live in a SMOG area you'll have to fix it, but there are some mudders that never have because they don't have to get emissions done.

I don't know about relocating the VSV to another location, when I did this repair I just put it back where I found it. I ran with the light on for over a month before I bought the valve.

Welcome to the board!

Buying a Factory Service Manual would be a good investment to help you trouble shoot in the future. It is always better to know what should b happening rather than try to use intuition.
 

landcruising

Mud User Not Abuser
Joined
Feb 1, 2007
Messages
743
Location
San Diego
 
 
I can garantee in California that if a smog ref saw a non toyota part and relocated EGR equipment it would be tagged as modified and would not pass emissions tests regardless of exaust readings. Most carefully check the sticker on the hood for routing and for required parts.
 

NLXTACY

Wits' End
Supporting Vendor
Joined
Dec 7, 2007
Messages
26,763
Location
West Hills, CA
 
 
Despite the negative tone of the first two posters I'd first say welcome :flipoff2: and I would also say congrats for taking it on yourself to try and trouble shoot even with the limited resources you have. I think we can all agree that the diode is a very temporary band-aid and is only there so you dont have to stare back at a CEL while you are driving and that you are going to eventually fix it. What I would do in your case is call some of the outfits here on mud and see if you can get a used one from CCOT or SOR or take a look at the classifieds section for someone parting it out. You could get it for just a few bucks. As far as relocating it I actually talked to my own smog person about that when I saw the first post about moving it. He said he totally understands the reasoning for moving it and would not himself even second guess it so long as it looks like its in a factory location. Meaning so long as dont mount it to the firewall or inner fender where it calls attention to itself you should be fine.

And X10000 on getting yourself an FSM, even if its the downloadable one.
 
Joined
Jan 16, 2007
Messages
45
Location
raleigh, nc
 
welcome:flipoff2: i didnt really have any trouble reading what you typed. it looks like your doing a good job tracing what may be the cause of your p0401 code. i will be following this thread b/c i have had the same code for a few weeks now and its time to fix. wish i had some insite on what should be done next:hillbilly:
 
Joined
Nov 16, 2003
Messages
6,045
Location
Dixie co. Florida
 
Solid diagnostic work :beer:


I have never seen anyone use a VSV from another manufacturer

I have not tried this but I have thought of it, Toyota uses a standard set of different kinds of common VSV's in all their vehicles, some open/close to filtered ambient, some port to a vacuum line like our EGR VSV, some closed when powered some open when powered, and then there are different brackets etc.


If you are short on funds you may want to go to your local pull-a-part,and see if you can find a similar one under the hood of a tercell or corola or 4runner or alike, my local yard would charge $5 for a handful of them, maybe bring a 9v battery for testing, you would likely need to put the new VSV in your old bracket but it should be do-able.

the plug may also be keyed different bring dikes and take plug with it, you can put your wires in the new plug for a water-proof fit.
 
Joined
Sep 10, 2008
Messages
2,132
Location
Calirado
 
 
First off welcome to this wonderful site :flipoff2:

By the way I followed your post no problem

NOW.... my next question..... since I am relocating the VSV, why couldnt I use one from a different vehicle that is much less expensive? as long as it is "open" when there is no voltage , and closed when there is..........

Has anyone ever done this? I just don't have the money for the Toyota one right now....
The only thing I can think of would be the diameter of the opening in the VSV allowing air flow. Think of drinking through a tiny straw vs. a large straw. I don't know if there is much variation in VSV sizing or how sensitive the EGR diaphragm is. You could try it and just see what happens I don't think you will hurt anything you'll just throw another code. I'm sure others will flame me if I'm wrong about the damage.

I have mounted mine outside the intake and zip tied it to the support arm, no need for a bracket. Intended as a temporary fix. Boy sounds like there is a red neck joke in there. You know if your a redneck if you have zip ties holding your engine together....:cheers:
 
Joined
Jan 19, 2009
Messages
7
Location
omaha, ne
Thanks for the last few responces...... I will keep them in mind.... I plan on a trip or two to the "u-pull it" here in the next couple of days when it warms up. we have been down near 0 and below for a while.... today we had a heat wave of around 30 with sunshine.... i had about an hour so to kill so i swapped out the front speakers that had been buzzing since i got it...

I do not live in a smog area and there is no kind of inspection here in Nebraska, so, as long as it goes down the road and I can stop it, i can title it and drive it.

in some other threads I have read here on the site, the reason for moving the VSV was to keep it cooler..... it seems that the heat from where it is located from the factory is the reason for its early demise.

the more I think about it, the more i may try and stick with a Toyota brand VSV.... it will most likely work in somewhat of the same manner.... I have checked and there are no landcruisers or lx450s around being parted out.... well, one, but it doesnt have any of the parts I need on it left .... besides, i would like to find a vsv from a different model that would work just to see if I can.... I seriously doubt if I am going to hurt anything in the process...... it will either block the vacuum line, or keep it open.... same thing as it has been doing for monthes now anyway.... right?
 
Joined
Nov 16, 2003
Messages
6,045
Location
Dixie co. Florida
 
The only thing I can think of would be the diameter of the opening in the VSV allowing air flow. Think of drinking through a tiny straw vs. a large straw. I don't know if there is much variation in VSV sizing or how sensitive the EGR diaphragm is. :
I do not think that will be a problem, the effective orifice size of the VSV only need be large enough to let more ambient pressure air into the EGR valve than the modulator is vacuuming out, the ports in the modulator are quite small. more VSV capacity will not hurt so the VSV is just on or off, shades of Grey and fine control come from the modulator.
 
Joined
Jul 14, 2003
Messages
2,195
Location
Hopewell NJ 08525
 
Welcome here :flipoff2: good work, since your the same type of person as me if its broke, take it apart since you can't break it anymore then it is .
Sound like your on the right track and hell cant hurt to try it . you'll be out a couple of bucks and a time .

Raven, this person lives in NE so finding a pair of dikes maybe a problem in the midwest. Plus how does a persons sexual preference help out at and scissoring help at the local pick and pull ? :confused: (though,:hmm: they would be more help then a couple of gay guys :doh:)
:hillbilly:


the plug may also be keyed different bring dikes and take plug with it, you can put your wires in the new plug for a water-proof fit.
 
Joined
Mar 27, 2003
Messages
12,520
Location
Somewhere in the foothills...
 
 
I just don't have the money for the Toyota one right now....
A couple of suggestions...

Check pricing from Cruiserdan. The original probably lasted 100-150k miles. You don't say what your mileage is but that is a guess. Getting a new one should get you to 300k miles so does it make sense to relocate and experiment with one from another vehicle? Only you can answer that question.

Your diagnosis process was sound but it should also include the resistance check of the VSV for EGR (you didn't mention that you checked the ohms). There is another very recent P0401 thread where I posted the FSM pages and how to test each component of the EGR system.

-B-
 
Joined
Jan 19, 2009
Messages
7
Location
omaha, ne
UMMMMMM no, I didnt sheck the ohms.... I will look up your thread and try and find it. My lx450 has 135,000 miles on it.... and you bring up a good point about the next one lasting till almost 300,000 miles. SO, my reply to that is simply... as easy as it finally was to get the VSV out from where it was, I really dont want to do it again.... I have already brought the wires and the vacuum hoses out , so that i can just reconnect the new one , find a bolt or two to mount it to, and be on my way....

many times i get so curious about things that I just go and fiddle with it before I have all the pieces I need to finish the job.... this relocation was mostly to make reinstalation faster when I do have the money to get the VSV.... Just yesterday I read the thread about the center locking diffs , and all i had to do was put in a switch.... so, I went out and pulled the dash apart and found the plug, moved a few switches around ( the security plug down by the rear heat, moved the rear heat over oneto accomodate) and used the hazzard swith to test... IT WORKED !!!!!!!!! i was so stoked... wow, the things you can learn from reading countless hours of ih8mud threads....... now i just have to find an orfus to pull a couple hundred out of for some parts....
and for the short time being, the resistor is keeping the check engine light off and it is running smoother than ever
 
Joined
Mar 27, 2003
Messages
12,520
Location
Somewhere in the foothills...
 
 
Joined
Jan 19, 2009
Messages
7
Location
omaha, ne
just some food for thought and you guys oppinion.... I know where a 96 LC is that belongs to a guy... it has been sitting in his driveway for about 5 years... it is pretty beat up, dents and some rust and soforth....... i went to him and asked him what he was going to do with it, he said he didnt know.... he went out one day and it wouldnt start... it has the front and rear locking diffs.... he said i could have it for $1000. considering i dont have $200 for the parts i need for mine, how much sence would it be to sell an organ to buy it ? How hard is it to put the locking axels on my LX? I have to assume that the engine may be shot.... i am not sure as to how much I believe him that it just wouldnt start one day ...... he has a Rangerover and a suburban in his drive also... i would think he would have it fixed if it wasnt something big $$$...? the tires are pretty much bald, leather seats are cracked , front and rear pass door are dented, brush guard is pushed back (had to pull pretty hard to get the hood open) Engine looked kinda clean. Brush had grown around the drivers side, so I didnt get a look at that side.... and no, i dont remember how many miles it has....

THOUGHTS ....? I think I would be ok without a kidney or a lung....

and the whole DIKE thing..... ummmm yea, I'll start a new thread about that one.....
 
Joined
Mar 27, 2003
Messages
12,520
Location
Somewhere in the foothills...
 
 
The axles are easily worth $1,000. Swapping to your LX is straight-forward and has been documented several times here on 'Mud. Your LX already has a lot of the wiring so that part of the job will be relatively easy.

If you are broke, you are broke and a good deal at $1,000 doesn't do much for you because you're still looking at expenses to do the swap.

-B-
 
Joined
Jan 19, 2009
Messages
7
Location
omaha, ne
Wow, that thread was super helpful, I have to say that i did all those tests for the mostpart... maybe not that scientific and precise, but in the same fasion and all passed, except for the VSV..... didnt do the ohms test, but i did run current across and no change.... I am now more than sure that this is what my p0401 was caused by.

THANKS
 
Joined
Jan 19, 2009
Messages
7
Location
omaha, ne
well, I headed out to the salvage yard today in search of a VSV that would work. I found a couple in some 4runners and celicas that I think will do the job... I will keep you posted....

Biggest excitement was finding a Center Diff Lock switch, or button mounted in a 97 Rav4.... popped it out... took it home.... HOLY S#*T.... it worked !!!!!!! only cost me a few $ and it fit perfect and functioned just as well. I also managed to get a whole uncut antenna out of the only landcruiser they had.. a 96... and a few hazzard switches too..... and the rear heater switch too (although for some reason, it didnt make it home.... will check the floorboard again tomorrow). I will probably throw the extra stuff I got on ebay here in the next couple days...

I am going to play with the vsv that I got and see what I can make work, it seems that their funcion is prettty simple.... they already have the same plug as the old one, they just have 3 nipples on them instead of two. cant imagine not being able to make at least one of them do what i want it to do.....
 
Joined
Apr 11, 2009
Messages
1
P0401 97 Manual RAV AWD

Hi Guys! You have no idea how glad I was when I stumbled on this forum. I am having the same dreaded P0401 code on my 97 Manual RAV AWD . I attempted to get to the VSV a number of times to no success. I tried the "going to the wheel well" instructions to no avail. I was able to "touch" the VSV from the top with my left hand going through the back of the engine with the battery removed, but that is as far as I can go. I have been driving with the CEL on for a few months now. I read the instructions of BEOWULF (.jpg images) and I was wondering if anyone can send the FSM pages on how to remove the air intake chamber as refered to by step #11 saying see page EM-27. Any tips from you guys will be appreciated. Thanks!
 
Joined
Mar 27, 2003
Messages
12,520
Location
Somewhere in the foothills...
 
 
Any tips from you guys will be appreciated. Thanks!
This is a Land Cruiser forum so none of the instructions regarding how to R&R components on a 1FZ-FE engine for a P0401 will apply to your RAV4. You can get electronic copies of the FSM for your RAV4 by accessing the TIS web site. The cost is nominal (~$10 for 1 day or maybe $15 for 2 days... new rates.)

-B-
 

Users Who Are Viewing This Thread (Users: 0, Guests: 1)

Top Bottom