ModernDayThorns

My mom has an 04 Mazda Tribute 2WD V6 DOHC.

It's idling extremly high, from 2,000 to about 3,500 RPM.
Took it to the local parts store and had them hook the scan tool up to it.
It threw the code: P0401-EGR flow insufficent.
Would the EGR cause it to idle this high?
I unhook what I think the sensors and wires to the EGR and nothing happens.
I can unhook the MAF Sensor and it idles down at around 700 RPM.

I'm just trying to get some input as to what the problem may be.
She's gonna have the EGR replaced, but I don't know if that's the problem.
Thanks for any help.

Fabrik8

There are three parts that can go bad usually on most recent engines: The EGR valve, the valve actuator, or the EGR pressure sensor. I'm making assumptions that all three are on that engine, which may be wrong. Anyway, see if you can look up some specifics about that code and what it may say, and that will point you toward a particular problem. Sometimes the problem isn't any of those three things and it's actually a clogged EGR port, and it just needs to be cleaned, but I don't think that would be the issue given how new the car is.
Oh, it could be something like the pressure sensor wiring also, but that would usually show up as a sensor fault or low voltage fault or something like that. I don't like to rule things out until there is enough information, but wiring is probably not the culprit because (again) the car is so new.

Do some research on that code, see what you find, report back and we'll see if we can help some more.

BAN HAMMER

it sounds lik your MAF sensor has something to do with it if you un-plugged it and the idle shot down...

Fabrik8

Unplugging the MAF will usually make the ECU default to a failsafe value depending on the engine management strategy, so that doesn't necessarily tell you anything and it's probably totally unrelated.

JETSWU87

+1

Colt45

I bet its a DPFE sensor, common problem on ford/mazda engines. It usually throws the po401 code, but not too sure if it would cause the high idle. I believe you have a 3.0L but on some of the newer 3.5L v6 fords, a faulty throttle body was causing sporadic idling issues. You may also want to call a Mazda dealer, sometimes they have an extended warranty for emissions related issues which this may qualify under.

ModernDayThorns

Thanks for the help. I'll have my parents call a stealership. I'll also look into the code some more. If I can't find anything I'll have my friend look it up on Shopkey or Alldata when he goes to school.