@mV33rs Check that your meter is in the right ohm range. If it's still that high it's probably bad. Probably the best way to check it is to apply 12vdc to the terminals with some wire from the car's battery or a nine 9v battery will probably work to, and if it clicks it's good, no click it's bad.
Awesome video! I was searching 1 year ago for something like this! I have a RAV4 1996, standard AWD and purchased the vehicle as used. It was ok for a while, then check light came on. But after a while there was a problem. Fuel consumption used to be 290 miles for a full tank and then it was only 100 for a full tank. I replaced the Oxygen sensor and that helped! But then (today). still the check light on and for a full tank I get 200 miles. Do you have a list with part numbers your replaced?
@Sed1999Rav4 No drivability Issues, just high emissions for the smog test. The Dorman VSV part is working fine, it's been in more than a year now. Although I have installed a Dorman transmission sensor in recent days that was bad out of the box, so disappointing!
Thank you so much for taking time to answer my questions
I have 1999 RAV4 with loss of power when the RPMs are between 1700-2500, somebody on the net says it is one of the VSV failing mode without a light
I do not have a light (No code), but I may have to replace my VSV, I found a 'Dorman' at RockAuto at $29, I am afraid to get this brand and be dispointed.
@Sed1999Rav4 The Dorman VSV worked for me and was a lot cheaper then the dealer(over a $100) I wouldn't think it would be the VSV without a light/code. My RAV was driving fine with this code but would get bad MPG's and fail the smog test.
I think somebody might be sending you down the wrong path. I hate for you to start changing parts and not fixing the problem. It could be a lot of things but to me it sounds like a fuel problem, weak fuel pump, bad fuel filter, bad/dirty injector.
Thank you for your advice, please check out this quote that I found on the net
"These are the symptoms of one failure mode of the EGR VSV (there are other failure modes where the CEL lights up). The rev range over which the hesitation / fluttering / jerking / stuttering occurs will depend on exactly how worn the EGR VSV is. - the broad range is 1,500 to 2,500 rpm, but may be narrower like 1,700 to 2,200 rpm.
This failure mode is where the EGR VSV is leaking, so that air is getting to the vacuum pipes and to the throttle body. If it leaks really badly it just admits air all the time, but pulsed flow.
I took the quote from a forum in RAV4WORLD the post was describing the same symptoms as what I am having with my RAV4.
I thought I’ll give it a try since the part is not that expensive and most people have replaced it
To respond to your question about the hesitation, I haven’t had the hesitation since I replaced the A/F sensor but the RAV4 struggle before going from third to fourth gear and sometimes it does not go at all!
@Sed1999Rav4 It's hard to diagnose the problem from my computer, I could only give a semi-educated guess. A vacuum switching valve (VSV) is a solenoid valve that controls the vacuum to the EGR valve either off or on. When the engine is cold the VSV is not energized stopping the vacuum from going to the EGR valve. When the engine warms up the VSV is energized allowing vacuum to flow to the EGR valve in which opens the EGR valve. There should be a diagram sticker under the hood.
With that being said I would recommend looking for vacuum leaks/kinked lines (I posted a link on how to find vacuum leaks in this videos description). You might want to try spraying the VSV's filter thing with some carb cleaner and see if anything happens. It can still be a fuel problem. I still find it unlikely that it's the VSV without a CEL light tho, but if want to try replacing the VSV it's inexpensive like you said. Let me know the outcome.
I am working on the fuel problem, I put some Chevron Techron (Fuel injector) on an empty tank then I fulled it up with premium gas (Super+) and it is running better but it not enough smooth like it should be.
Any advice and tricks how to check injectors and clean them.
@Sed1999Rav4 I doubt it's the injectors, I would put that at the bottom of the list. I would look into the air/ignition system, cleaning the throttle body with throttle body/carb cleaner, cleaning mass air flow sensor with special mass air flow sensor cleaner, rotor/rotor cap, spark plugs (use the oem denso standard ones), etc. Again I'm not a expert here.
Is your RAV four wheel drive? I read that getting at the VSV valve is difficult on the 4 wheel drive version. I've got a 1998 RAV4 with the PO401 code.
@dennisunay It's a pain, there's two small nuts on top that holds it on to the studs of the engine and a big nut at the bottom from the exhaust. I think I used a small crescent wrench on that one. What makes it so hard there's not a lot of room between the engine and firewall. So be sure it's bad before removing it. Test it with the engine on and apply vacuum to the EGR valve vac port (I used a vac line from the throttle body to make it easy) and if the engine dies or almost dies it's good.
I dont know if I read it wrong but mine has about 1800 ohms of resistance
mV33rs 1 week ago
@mV33rs Check that your meter is in the right ohm range. If it's still that high it's probably bad. Probably the best way to check it is to apply 12vdc to the terminals with some wire from the car's battery or a nine 9v battery will probably work to, and if it clicks it's good, no click it's bad.
joe1951 1 week ago
@joe1951 just checked, 9v doesnt click, 12 volt it does click :)
mV33rs 1 week ago
@mV33rs Ok good, well I thought the 9v battery might work, good thing you tried the car battery.
joe1951 1 week ago
Awesome video! I was searching 1 year ago for something like this! I have a RAV4 1996, standard AWD and purchased the vehicle as used. It was ok for a while, then check light came on. But after a while there was a problem. Fuel consumption used to be 290 miles for a full tank and then it was only 100 for a full tank. I replaced the Oxygen sensor and that helped! But then (today). still the check light on and for a full tank I get 200 miles. Do you have a list with part numbers your replaced?
hardtrance9 1 month ago
Have you had any drivability issues when you had this code P401, or just it did not pass the smog test?
Now, do you have any issues with the "DORMAN" part?
Thanks a lot
Sed1999Rav4.
Sed1999Rav4 1 month ago
@Sed1999Rav4 No drivability Issues, just high emissions for the smog test. The Dorman VSV part is working fine, it's been in more than a year now. Although I have installed a Dorman transmission sensor in recent days that was bad out of the box, so disappointing!
joe1951 1 month ago
@joe1951
Thank you so much for taking time to answer my questions
I have 1999 RAV4 with loss of power when the RPMs are between 1700-2500, somebody on the net says it is one of the VSV failing mode without a light
I do not have a light (No code), but I may have to replace my VSV, I found a 'Dorman' at RockAuto at $29, I am afraid to get this brand and be dispointed.
Your thoughts are really appreciated.
Again thank you so much.
Sed1999Rav4.
Sed1999Rav4 1 month ago
@Sed1999Rav4 The Dorman VSV worked for me and was a lot cheaper then the dealer(over a $100) I wouldn't think it would be the VSV without a light/code. My RAV was driving fine with this code but would get bad MPG's and fail the smog test.
I think somebody might be sending you down the wrong path. I hate for you to start changing parts and not fixing the problem. It could be a lot of things but to me it sounds like a fuel problem, weak fuel pump, bad fuel filter, bad/dirty injector.
joe1951 1 month ago
@joe1951
Thank you for your advice, please check out this quote that I found on the net
"These are the symptoms of one failure mode of the EGR VSV (there are other failure modes where the CEL lights up). The rev range over which the hesitation / fluttering / jerking / stuttering occurs will depend on exactly how worn the EGR VSV is. - the broad range is 1,500 to 2,500 rpm, but may be narrower like 1,700 to 2,200 rpm.
Sed1999Rav4 1 month ago
Continued ...
This failure mode is where the EGR VSV is leaking, so that air is getting to the vacuum pipes and to the throttle body. If it leaks really badly it just admits air all the time, but pulsed flow.
"
Sed1999Rav4 1 month ago
@Sed1999Rav4 Was this quote you got a problem from a Toyota?
Does your engine hesitate when you rev between 1700-2500rpm's in park?
Sure it's possible, basically some kind of vacuum leak causing a lean condition.
However I find it unlikely without a CEL light that comes on. Toyota's have picky emission controls, even your quote has a CEL that lights up.
joe1951 1 month ago
@joe1951
I took the quote from a forum in RAV4WORLD the post was describing the same symptoms as what I am having with my RAV4.
I thought I’ll give it a try since the part is not that expensive and most people have replaced it
To respond to your question about the hesitation, I haven’t had the hesitation since I replaced the A/F sensor but the RAV4 struggle before going from third to fourth gear and sometimes it does not go at all!
Any idea, I really appreciate.
Sed1999Rav4 1 month ago
@Sed1999Rav4 It's hard to diagnose the problem from my computer, I could only give a semi-educated guess. A vacuum switching valve (VSV) is a solenoid valve that controls the vacuum to the EGR valve either off or on. When the engine is cold the VSV is not energized stopping the vacuum from going to the EGR valve. When the engine warms up the VSV is energized allowing vacuum to flow to the EGR valve in which opens the EGR valve. There should be a diagram sticker under the hood.
joe1951 1 month ago
@Sed1999Rav4 Continued...
With that being said I would recommend looking for vacuum leaks/kinked lines (I posted a link on how to find vacuum leaks in this videos description). You might want to try spraying the VSV's filter thing with some carb cleaner and see if anything happens. It can still be a fuel problem. I still find it unlikely that it's the VSV without a CEL light tho, but if want to try replacing the VSV it's inexpensive like you said. Let me know the outcome.
Jon
joe1951 1 month ago
@joe1951
Thank you Joe;
As you said the VSV is fine.
I am working on the fuel problem, I put some Chevron Techron (Fuel injector) on an empty tank then I fulled it up with premium gas (Super+) and it is running better but it not enough smooth like it should be.
Any advice and tricks how to check injectors and clean them.
Again tanks a lot.
Sed1999Rav4 2 weeks ago
@Sed1999Rav4 I doubt it's the injectors, I would put that at the bottom of the list. I would look into the air/ignition system, cleaning the throttle body with throttle body/carb cleaner, cleaning mass air flow sensor with special mass air flow sensor cleaner, rotor/rotor cap, spark plugs (use the oem denso standard ones), etc. Again I'm not a expert here.
Thanks for watching
joe1951 2 weeks ago
@Sed1999Rav4 You might want to ask a real mechanic.
Try this guy: Scotty Kilmer he has a youtube channel and you can send him a email with your question at: scottykilmer@gmail.com
joe1951 1 month ago
Is your RAV four wheel drive? I read that getting at the VSV valve is difficult on the 4 wheel drive version. I've got a 1998 RAV4 with the PO401 code.
Flatulating 4 months ago
@Flatulating No, mine is 2wd. I would imagined that the 4wd would make it interesting.
joe1951 4 months ago
Good video... Did the EGR modulator replacement keep the P0401 off or did it return?
FreakShow2008a 7 months ago
@FreakShow2008a Yes, It's been off for a year now.
And good luck to you dude.
joe1951 7 months ago
How did take off the egr valve?
dennisunay 7 months ago
@dennisunay It's a pain, there's two small nuts on top that holds it on to the studs of the engine and a big nut at the bottom from the exhaust. I think I used a small crescent wrench on that one. What makes it so hard there's not a lot of room between the engine and firewall. So be sure it's bad before removing it. Test it with the engine on and apply vacuum to the EGR valve vac port (I used a vac line from the throttle body to make it easy) and if the engine dies or almost dies it's good.
joe1951 7 months ago
@boris2153 Dude you're welcome
joe1951 9 months ago
Wow, very nice video. Shows more than one possibility.
Thank you.
DonMecanico 1 year ago
@DonMecanico Hey thank you, this seems to be a common problem for the rav. I'm just glad to see that this video can help someone.
joe1951 1 year ago
Thank you for the info! Very helpful! =)
MikeMiheli 1 year ago
@MikeMiheli Thanks, I know there's a lot of info on the screen lol.
joe1951 1 year ago