Engine light on ..code P0401

[drwho]

Good Morning Everyone:

I have a 2000 Camry with 108,000 miles. Just changed the Oxygen sensor.

My Engine light is on....OBDII read out is P0401. I have done the following:
1) removed EGR valve and cleaned and honed EGR ports
2) removed modulator top and cleaned out the filter

I have read that the most common problem with this code is the vacuum
switching valve. I followed the vacuum lines from the modulator and EGR
valve and finally found the VSV from underneath. I don't have a hoist...just
got on my back on the street after putting car on the curb. The problem is
I can't get to the 12mm bolt that holds the unit to the block. I can't even see it.
I am just a Saturday/Sunday mechanic. Can anyone help out and give directions as to how to remove that 12mm bolt. Thank you.

[Chris Crash]

Laying on your back again, follow the lines, and just feel around. Maybe get a mirror and try to find it.

Once you feel it, get a socket on there with an extension or two, maybe a wobbly joint, and try to take it off. If you're skinny armed, you can also reach it from the top by going behind the AC lines and going behind the engine, again working by feel, it is right under the intake.

Hope this helps!

[drwho]

Thanks for the reply.......I hope I can do this.

[Bruin4thgen]

Hi, I just had to get my boyfriends 2000 camry to pass smog. The cel had been on intermittently for a couple months but car ran fine. Evventually it stayed on 24/7 and never would pass that way. Code was p0401 so we removed the modulator and cleaned filters. The dirty thing was the hoses, one was full of black dust that made a cloud when blown out. Cleaned erg valve itself too but not really dirty.

Light was reset and stayed Off for 2 weeks, but then returned.

Like the OP we decided that it must be VSV. had just finished a miserable repair on sisters car that had gone horribly awry so wasn't very excited to start.

Dealer wanted $90 for VSv so Pepboys won @ $60.

There is a good VSV replacement tutorial on a Tundra site. The thing not mentioned there is that easiest way to see the VSV is to remove passenger side tire. You can clearly see it and 12mm bolt then through opening. I thought it would be easy since I could see it and everyone a bunch of whiners. 2 or 3 hours later I was done !!! Impossible to see it and have wrench on it. Also, some structure hits back of hand just perfectly when you have fingers on it. Keeps you from twisting with fingers.

Somewhere there is a Toyota engineer keeping mechanics in work. Did I mention that sine engine is tilted backwards, the nut wants to fall out of brackets when you try to get it in hole? The other treat was that there is a place right under there where the bolt can fall and get to a place you vantage reach? Motor mount right below has perfect Black Hole of Calcutta. Hint: there are other similar bolts holding radiator in.

I finally got bolt threaded by using chewing gum to hold bolt in socket. I was thrilled beyond words when thread actually caught.

I was less thrilled when 20 miles later the light came back on.

By all accounts the modulator is 2nd most likely cause so back to Pepboys we went.

The part was like $50 and was Identical to existing one.

Snapped it in and reset codes. Light has stayed off and car barely passed smog.

We have 2 years to worry about why it's 15 mph numbers were so bad but 25 mph good.

Lesson learner... Replace modulator first. MUCH easier.

[drwho]

Thank you for the info. I will replace the modulator first....that is easy. Hope that will clear the code.
Thanks again.

dr who.

[Yuko]

Replacing the EGR VSV without a lift is possible. The VSV costed me a $1 at the salvage yard. To get to it, the front wheels had to be turned to the left. Then it can be reached with a 10mm socket, u-joint, 10" extension, and racket from the wheelwell. It took me less than an hour to change it and 35K miles later; still no P0401.

Here the pic of the VSV (red arrow) on My Gen 2001. It's held on by one 10mm bolt and has two vacuum lines and one wire plug.

[drwho]

Thanks for the pic. and info. Code P0401 is tricky. Will try a salvage yard for the part.
Thanks again.

Dr Who