please help p0401 code

03 4x4 2.7L 5spd.......so i was driving the other day and got a check eng. light on p0401.......took it to the dealer and a master tech took a look....he said replace the egr valve and vsv solinoid . so i did this and the light came back on.

prior to replacing these parts i checked out the egr with a vacuum gauge(applied vacuum and engine wanted to stall, so i figured it was ok)
removed the vsv and applied vacuum then actuated it with battery voltage , vacuum released- figured that was ok too)
looked inside egr to exhaust manifold tube and its completely clear!....wtf!

anybody have this problem?

thank you

 

lmao, I have the same code right now. Hope we can find someone here with the same issues and got them fixed.

 

ttt

 

Try this guys:
http://www.tacomaworld.com/forum/2nd-gen-tacomas/68572-help-check-light-why.html#post1290647

 

Thanks bud, great list of codes. Only problems is "P0401 Exhaust Gas Recirculation Flow Insufficient Detected" is giving this moron (me) enough to go by. How about a few more details. There are vacume chambers, vsv and other items that are included in the EGR flow....

 

Yer talking to a dummy here bud. I can sure fix a truck that don't have a computer, try me on carburetors, distributers and points and I'm ok. Throw a "code" at me and I'm,,,, WTF??????

There some pretty smart people on here (Chris 4X4 and a bunch more) who can answer your questions....good luck.

 

Ben to the rescue!!!!

 

Thank you Ben so much!
I'll mess with it tomorrow.......
Do you have a vacuum diagram also?

 

the vacuum ports on top of the throttlebody seem to be the problem......
two are clogged so i blew them out and checked for vacuum with a gauge.......i have vacuum now and i reset light so now i will post eng. light results in a few days.

 

no light yet, its been about 75-100 miles......it was the two throttlebody ports 2nd/3rd from butterfly opening on top.

 

P0401 Exhaust Gas Recirculation Flow Insufficient Detected

 

i had this same code for over a year, it would come on and off so i never addressed it. now it just stayed on, and i have dmv reg at the end of the month. spent the afternoon diagnosing.
found there was vacuum off the throttle body(to port P), but nothing after the vacuum modulator(out of port Q).
i was pretty sure this was the culprit, decided to crack open the modulator to see. sure enough, the rubber membrane was broken/cracked.

 

I get the P0402 code from time to time as well. I just reset it using the OBD-II computer I keep under the seat and continue driving. The cost of replacing this item at retail is just stooopid expensive. too!

 

Gas cap