I've been to two mechanics..spent $200.

What did u spend those $200 dollars on?

I got the similar prob and the car been running fine since the summer. Went to autozone for that general diagnostic and they say its the PURGE valve thats messed up... (Yea, been driving with the light on since like early July-BUt, car still great)

I don't have the money to do the repairs yet....

 

According to Toyota's schematics that another member graciously sent me, the trouble areas maybe;

EGR valve stuck closed.
EGR Vacuum Switching Valve (VSV).
EGR VSV open circuit.
EGR valve position sensor open or short circuit.
EGR valve position sensor.
ECM.

I could email you a copy if you want, but it's mechanic gibberish.

I had a P0401 before and it turned out to be a spliced vacuum line. Hopefully you'll be as lucky as I was.

 

I spent the money on diagnostics and resets. AutoZone can't give the free tests in our area any more--pressure from the mechanics union or some such thing. It is a valve problem for sure. I talked to a mechanic who sounded much more knowledgeable than Marin Toyota..who seemed nice but clueless. Evidentally, it has to be test driven a special way after repair, to see if the fix sticks. Bummer, but we are in an "enhanced" smog zone here--just have to bite the bullet, I guess. Thanks for your help, fellas. I think they see me comin' a mile away!

 

It would be a good start, letting us know what kind of car and engine it is.

 

Of course. Sorry. It is a Toyota Rav 4 - 1998, 4 whl drive. It has 72K miles on it and it is manual shift (Must be a 4-cylinder, I guess).

 

replace the vsv on the back of the head.

 

Thank you DeeKay140...you sound pretty certain. Actually, that is what the Toyota guy said, but, he said, he could not be sure that was it (he sounded VERY equivocal)...and it would cost about $96 for the part and $180 labor to find out. Plus he didn't mention the test drive--(the other mechanic said I could not do the test drive properly and he had to do it). Does this make sense to you? Do you think I should just go ahead with it then? Quig.

 

the problem is usually intermittent, that is also a 2 trip detection trouble code.( meaning the car has to see a certain set of bad values on 2 seperate key cycles) The part is about 80-95 dollars at toyota, its an ez repair,but hard to get to. its even tougher on the rav 4x4

I am a toyota master tech. so I am giving u sound advice. The vsv is the most common problem. if the egr itself was sticking, the car would stumble or die on decel.

The problem is , when u remove the part and test it, it sometimes tests ok. so its kinda of a educated guess by process of elimination.

If the part was bad all the time. u could clear the codes by disconnecting the battery. then drive it for a day and it should come on fairly quickly.. you drive the car up to 50 mph or so. stop, turn the car off, restart it and do it again. if the part was shorted, the chk eng light should come back right away..


good luck and keep us posted.

 

part no.?

the problem is usually intermittent, that is also a 2 trip detection trouble code.( meaning the car has to see a certain set of bad values on 2 seperate key cycles) The part is about 80-95 dollars at toyota, its an ez repair,but hard to get to. its even tougher on the rav 4x4

I am a toyota master tech. so I am giving u sound advice. The vsv is the most common problem. if the egr itself was sticking, the car would stumble or die on decel.

The problem is , when u remove the part and test it, it sometimes tests ok. so its kinda of a educated guess by process of elimination.

If the part was bad all the time. u could clear the codes by disconnecting the battery. then drive it for a day and it should come on fairly quickly.. you drive the car up to 50 mph or so. stop, turn the car off, restart it and do it again. if the part was shorted, the chk eng light should come back right away..


good luck and keep us posted.

Hi DeeKay,

I have the RAV4, 1996, 4WD version and havieng the same problem with check engine light. Summary:

- Bought the car in November (used of course)
- Afer maybe 3-4 weeks, check engine light went on
- Car didn't stumble or so, and fuel economy was ok
- Took it to the Toyta dealer, scanned and found that oxigen sensor was the potential problem
- Guys there deleted and asked me to test and come back in a couple of days
- Same day I went out, check engine light (CEL) came on again
- This time I was having BIG fuel econmy problems (100 miles for full tank!)
- Also the car was stumbling badly and smell like a lot of gasoline
- Took to the dealer again, this time was not the oxigen but the MOP? sensor
- They were sure it was that. They ordered and replaced the MOP
- After this fuel consumption went ok, car didn't stumble at all
- Before arriving home, again the CEL went on!
- This time fuel consumption was ok, no stumbles either
- Found an AutoZone & got it scanned. Error showed EGR valve and selenoid flow problem
- Days after took it to the dealer, had the EGR cleaned (free of charge), deleted the error codes again
- Again, everything was nice, but just before my home (50 miles from the dealer) CEL went on again.
- This time everytime I turn on the car it revs at 2,000 rpm. After gets warm will drop to 1,100 rpm's (not the lovely and stable 900 rpm's)
- Also this time the car stumbles sometimes strong specially at very low speeds

- Have been reading recently on what to do.
- I decided to go for the VSV valve.
- Called the dealer and they said that most probably by cleaning the valve problem can get fixed.
- As the dealer is far away, I need to order in advance the part (VSV) so I can use my time better (just don't have the time to go back and forth so many times)

- Read there are two VSV... at the dealer they said they know there is a VSV and PVSV?

- Do you have by any chance the part no. so they won't get mixed up on which part to order and replace?

- Do you have any other suggestions on what the problem can be? (before I was about to replace the EGR but stopped after reading on the VSV).

Please help, this is so so so so frustrating...

 

Well, thank you! It is so nice to get sage advice from an expert! I'll try the disconnect battery thing this weekend.

 

EGR Check Engine Code and 1998 Toyota Camry

I have the same problem -- the check engine code has been on nonstop but the car was running fine. I had the oil changed, and brake pads replaced and had them pull the code -- mechanic said that it was 1 single code for EGR -- could be something simple or not. He cleared the code and told me that he wouldn't really affect anything except my emissions (my car passed the NOVA/DC emissions test this year). The check engine light came back on again after about 20 miles -- should I have him look into it further? please help. --

Oh -- it is a 1998 Toyota Camry Automatic 4 Cyl. with approx 50k miles on it.

 

replace the vsv as stated in this post.

 

yeah replace the egr vsv, lots of problems with those. to make absolutely suer the diag steps are as follows. start the engine, connect a hand held vacuum pump to the rubber hose coming off the egr valve, apply vacuum to it if it tries to kill the engine, the egr valve itself is working properly, (it adds spent exhaust gases to the incoming air charge therefore reducing the temperature of the combustion chamber during combustion, lowering the production of harmfull gases).... next see if the intake is sending enough vacuum to the vsv to operate the egr valve, this is done by connecting a vacuum gauge to the modulator ( a round plastic with a red metal top with 3 ports coming out of the sides, loctaed on the top of the intake manifold next to the throttle body) connect the gauge to the Q port and open the throttle to approximatly 3000 rpm, the guage should read around 20 inches of vacuum, if it doesnt check the vacuum hoses that connect to the front of the throttle body if the are good replace the modulator, if it does pull 20 inches check the lines that go to the vsv, if they check ok then by the process of elimination, the vsv ( vacuum switching valve, which opens when told to do so by the ecm providing vacuum to the egr) has to be the problem.

 

yeah replace the egr vsv, lots of problems with those. to make absolutely suer the diag steps are as follows. start the engine, connect a hand held vacuum pump to the rubber hose coming off the egr valve, apply vacuum to it if it tries to kill the engine, the egr valve itself is working properly, (it adds spent exhaust gases to the incoming air charge therefore reducing the temperature of the combustion chamber during combustion, lowering the production of harmfull gases).... next see if the intake is sending enough vacuum to the vsv to operate the egr valve, this is done by connecting a vacuum gauge to the modulator ( a round plastic with a red metal top with 3 ports coming out of the sides, loctaed on the top of the intake manifold next to the throttle body) connect the gauge to the Q port and open the throttle to approximatly 3000 rpm, the guage should read around 20 inches of vacuum, if it doesnt check the vacuum hoses that connect to the front of the throttle body if the are good replace the modulator, if it does pull 20 inches check the lines that go to the vsv, if they check ok then by the process of elimination, the vsv ( vacuum switching valve, which opens when told to do so by the ecm providing vacuum to the egr) has to be the problem.

Thank you so much for this info! This helped me fix my problem with my 2001 Camry (4 cyl), 150K miles. Unfortunately, I didn't read toyo_tech02's post before I started trying to fix things. I wasted a lot of time and frustration removing my EGR valve for nothing. I could have skipped that step altogether. It wasn't even really dirty. But cleaning the EGR valve did not resolve my P0401 error.

Here's what I did after reading toyo tech's post. I bought a hand vacuum pump and a vacuum gauge from amazon for like $50 total. Buying the separate gauge was probably unnecessary because the hand pump has its own built-in gauge. So if you want to do this on a budget just get the pump with the gauge (warning- the lines that came with the pump were way too big for the toyota connectors).

1) I connected the pump to the EGR valve's vacuum line on the top. With the car running I used the hand pump to activate the EGR valve and the engine struggled desperately, almost stopped completely. If creating a vacuum doesn't make your engine bog down then it means the exhaust is not making its way through the EGR valve and into the intake manifold, which would mean the valve is not working properly or the valve or pipe that it connects to is clogged with carbon. But because it made my engine struggle that meant I could move on to the next step.

2) The EGR modulator is what sends a vacuum from the engine to the VSV. I connected the vacuum gauge to the Q port on top of the modulator and revved up the engine. I saw NO vacuum whatsoever on the gauge. So I ordered a replacement EGR modulator from rockauto.com (I bought the cheapest model for like $30 with shipping). I then replaced the modulator (doesn't require any tools, just pulled it from its bracket and disconnected the 4 vacuum lines). I have read a lot of conflicting information online about testing an EGR modulator. Some people say to blow on one port while plugging the others, but different people say different things about what the results tell you. Long story short, I connected my vacuum gauge to the Q port of the new modulator and the vacuum responded to the throttle. In fact it looked like a tachometer. The modulator has a filter which was completely fouled. Plus it has a diaphragm or membrane inside which isn't serviceable.

I reset my CEL code (using a cheap OBDII scanner that I got on ebay for about $30) and drove around multiple times. The CEL hasn't returned (knock on wood). Incidentally, what I discovered is that if the computer receives a P0401 code it will initially store an internal pending code which I believe does NOT activate the CEL light. It's only after you turn off the car and drive it again that the light will come on (after it fails a second time). So don't get your hopes up if the CEL light doesn't come back on after making a repair. It might not happen until the next trip. Moral of the story is to buy yourself a cheap OBDII scanner so you can see "pending" codes as well as regular codes.

3) Fortunately, I didn't have to change the VSV which looks like a pain to get to. I don't have a floor jack so I lucked out. But apparently you have to jack up the car and get to it through the front-right wheel well. It looks pretty much impossible to replace unless you can lift your car. But if the vacuum gauge did show a vacuum on the modulator's Q port (when you rev the engine) then I would have had to replace the VSV next.

Quick summary:
1) Apply vacuum to EGR valve while running. If it dies or struggles, your EGR is good.
2) Check vacuum on the modulator's Q port. If there's a vacuum when you rev up, then your modulator is good.
3) If modulator and EGR valve are both good, and vacuum lines are good, then it's probably the VSV.

Thanks again to toyo_tech02!!!!

Good luck to all!
-Mike

 

yeah replace the egr vsv, lots of problems with those. to make absolutely suer the diag steps are as follows. start the engine, connect a hand held vacuum pump to the rubber hose coming off the egr valve, apply vacuum to it if it tries to kill the engine, the egr valve itself is working properly, (it adds spent exhaust gases to the incoming air charge therefore reducing the temperature of the combustion chamber during combustion, lowering the production of harmfull gases).... next see if the intake is sending enough vacuum to the vsv to operate the egr valve, this is done by connecting a vacuum gauge to the modulator ( a round plastic with a red metal top with 3 ports coming out of the sides, loctaed on the top of the intake manifold next to the throttle body) connect the gauge to the Q port and open the throttle to approximatly 3000 rpm, the guage should read around 20 inches of vacuum, if it doesnt check the vacuum hoses that connect to the front of the throttle body if the are good replace the modulator, if it does pull 20 inches check the lines that go to the vsv, if they check ok then by the process of elimination, the vsv ( vacuum switching valve, which opens when told to do so by the ecm providing vacuum to the egr) has to be the problem.

Awesome response!! A++!! :thumbup:

 

Toyo_Tech and Deekay:

I am a newbie 99 4runner 2wd 2.7 owner. Just bought the car and got CEL the next day. I am getting a p0402 code which is Excessive EGR flow. Could the vsv and modulator cause this code as well as the p0401?

Thanks,
Stan Henley

 

Its probably stiil the vsv (stuck open instead of closed) I would also ohm out the gas temp. sensor. should be around 2000 ohms when warm.

 

You Da Man!!!!!,Deekay

I replaced the Vsv for EGR yesterday afternoon. I was amazed at how much better the engine immediately ran even though I had no previous reference point since I just bought the car.

The engine (2.7) had been a bit "surgy" when cold, which I thought pretty normal, and felt as if it were working too hard. It would downshift to twice going up some hills on the interstate with the Cruise control on.

Now it rarely downshifts, has a lot more power, is much smoother and more stable, and fuel consumption seems to be much better. Man, the VSV is a "Wonder Valve"!

I just knew that since I bought the car from a small car lot up in the "Latin" area of Atlanta that I might be in trouble since the business was far away and noone there spoke very good English. ;0)

Oh well, all's well that ends well. I just love this car and YOU ARE DA MAN!!!

Thanks, Stan Henley
Palmetto, GA
1999 2.7 2wd Limited

 

i have 96 lexus es300 with same code so I bought new vsv valve and installed it. CEL is still on, should I go ahead and reset it or should I wait for CEL to clear itself?

 

I read some of the post to which you have expertly answered. I am writing with the same hope of finding a way through my issue.

I have a Toyota Camry CE 2000 model. The engine check light has come on. The code it gives is P0401 that translates to Insufficient EGR flow. However, my car is running just fine. There is no change in whatsoever can be observed while driving.:hammer:

The engine check light came on (on day one) after I pressed the brake paddle for several times while car was parked and ignition was off.

Though, the light went off automatically (on day two), and then I drove almost 50 miles. But on day three it came on again. All automatically. And it has been on since then.:headbang:

Can you suggest how to fix the problem. I am from Ames, Iowa. Do you know a good mechanic who can fix the problem.

Waiting your earliest reply.

Thanks,

 

you need to buy and install EGR modulator. I have found best price on this site www.parts.com Once you install it you can drive for a couple days and light should turn off by itself (it did on my mother's car) Once computer runs a check it will turn off CEL on its own, you dont need to clear it.

 

My parents had the same code P0401 on their '06 4 cyl Camry. First thought gas cap was on too tight, (per local Toyota mechanic). This fixed the problem for about 3 days. Code popped again, replaced gas cap. That was 2 years ago.

That worked for us, I guarantee nothing, but worth a try.

Good luck.

 

Tony, I'm thinking I have the same problem as your parent's car. I also have an '06 Toyota Camry 4 cyl and the CEL is on with code P0401. PepBoys said it might be the EGR, however I was originally thinking a gas cap problem because the light came on right after a fillup. I am going to try to replace the gas cap first and will let everyone know the results. Thanks for the info.

 

To fix the code P0401 and P0446 on a Toyota Camry or Solara you will need to buy two parts (and no you don't have to replace the EGR Valve):

1. EGR VSV (Vacuum Switch Valve) part# 90910-12080 to get rid of the P0401 code * Located behind engine. Around $50 bucks.

2. Vapor Pressure Sensor VSV (Vacuum Switch Valve) part# 90910-12271 to get rid of the P0446 code (and also P0440, P0441) It is located on the bottom rear of the car near the Charcoal Canister (and no you don't have to replace the Charcoal Canister). Around $60 bucks.

*You might also need to replace the EGR Vacuum Modulator part# 25870-74090 if the P0401 code comes back. You can pop the hood and replace that by hand, it's easy. Around $60 bucks.

Try not to buy these at the dealer since they like to rip people off. After you get the parts (don't buy used since these parts get carbon dirty!), pay a mom and pop mechanic for the labor to do it since you don't have tools and a jack/lift for access, and they are much cheaper than the dealers.

 

A BIG Thank You

I followed Toyo_Tech02's advice and man was it ever spot on. I recommend this for Camry owners. My roommate had been dealing with the Check Engine Light for about 3 years. He paid numerous "mechanics" to fix the problem, but the light always came back on. This includes "certified" Toyota mechanics. Thankfully, we have guys like Toyo_Tech around We followed the testing advice as closely as possible using rented tools from Advance Auto. Noted that everything in the system was performing just as specified in Toyo_Tech's post. Then we purchased the EGR VSV, put the vehicle on a lift, did the replacement, and 30 mins later had no CEL. It's now been over 3 months and everything is working wonderfully.

Thank you for the great advice

 

I just recently had a P0401 code as well. I already had cleaned out the egr and the CEL still stayed on. After replacing the vsv the code and CEL are now erased

 

Easy way to replace EGR VSV

Ok,
If you folks have done all the diagnostics and found that you have to replace the EGR VSV on a 2.2 Camry here is the easy way.

First of all, don't even try to get the old one out!!
Just unplug the 2 vacum lines and the electrical connector from the old VSV.
(leave the old VSV attached to the engine)

Next from the top of the engine (standing on the passengers side) pull up the 2 vacum lines and the electrical connector you just pulled off the old VSV.

Now look down at the firewall and look for the lower brake line bracket mounted to the firewall.
Unscrew its retaining nut.
Attach your new VSV (the bracket is included and mounted to the VSV when you get a new one) to the brake line bracket, reinstall the previous retaining nut to the brake line bracket.

Attach the 2 vacum lines and the electrical connector to the new VSV.
Finished ..done... drive away.

Took me 30 minutes

 

Ok,
If you folks have done all the diagnostics and found that you have to replace the EGR VSV on a 2.2 Camry here is the easy way.

First of all, don't even try to get the old one out!!
Just unplug the 2 vacum lines and the electrical connector from the old VSV.
(leave the old VSV attached to the engine)

Next from the top of the engine (standing on the passengers side) pull up the 2 vacum lines and the electrical connector you just pulled off the old VSV.

Now look down at the firewall and look for the lower brake line bracket mounted to the firewall.
Unscrew its retaining nut.
Attach your new VSV (the bracket is included and mounted to the VSV when you get a new one) to the brake line bracket, reinstall the previous retaining nut to the brake line bracket.

Attach the 2 vacum lines and the electrical connector to the new VSV.
Finished ..done... drive away.

Took me 30 minutes

I know that this is old BUT hands down this is the EASIEST way to do this job on the 2.2 Camry!!!!!
THANK YOU!!!!

 

I need some help, I replaced vsv now, but light is still ON , what could go wrong here ?