EGR P0401 insufficient flow after flashing Base US93/EU98 map

Discussion of tuning specific to MAZDASPEED6/MAZDASPEED Atenza/Mazda 6 MPS vehicles
amiara
Posts: 18
Joined: March 20th, 2022, 11:22 pm

EGR P0401 insufficient flow after flashing Base US93/EU98 map

Post by amiara »

Hi

I just flashed the Base EU98 and got this error after driving 25km! my car did not like the tune :oops
mituc
VersaTuner guru
Posts: 1324
Joined: December 17th, 2011, 2:47 pm
Location: Iasi/Romania

Re: EGR P0401 insufficient flow after flashing Base US93/EU98 map

Post by mituc »

The tune has nothing to do with the function of the EGR, EVAP or VTCS subsystems, they are controlled by subroutines in the ECU which are not touched in any way by these tunes. There's a chance your car has EGR blocked or defective and the previous owner (did you buy the car recently?) disabled the corresponding code.
2008 Cosmic Blue Mazda 3MPS
Built engine + WMI + GTX3071 gen2, ~509BHP @34PSI
2008 Icy Blue Mazda CX7
Stock engine and exhaust (YES!!), JBR3" + GTX2867 gen2 + Autotech HPFP, self-tuned to 330-ish BHP
amiara
Posts: 18
Joined: March 20th, 2022, 11:22 pm

Re: EGR P0401 insufficient flow after flashing Base US93/EU98 map

Post by amiara »

Ok thanks! so i unplugged the EGR valve and disabled DTC error for EGR.
Maxl
Posts: 10
Joined: January 8th, 2021, 1:05 pm
Location: Germany

Re: EGR P0401 insufficient flow after flashing Base US93/EU98 map

Post by Maxl »

Hello,

I had the same error after installing versatune. I also thought it was coincidence. Then later I installed a egr block off plate and disabled the error. Now because of other reason I removed Versatune from my car but I let the block off plate installed and I don't get any errors. I don't know why but maybe something is different to the software of US to Europe Mazdas...

I also noticed a little different cold start processing between oem software and versatune but that's an other topic...
mituc
VersaTuner guru
Posts: 1324
Joined: December 17th, 2011, 2:47 pm
Location: Iasi/Romania

Re: EGR P0401 insufficient flow after flashing Base US93/EU98 map

Post by mituc »

At some point I used a block-off plate for my EGR to track down a different issue, never got any errors even though the EGR related PIDs were never disabled. I found it weird at the moment but this is how it went.
2008 Cosmic Blue Mazda 3MPS
Built engine + WMI + GTX3071 gen2, ~509BHP @34PSI
2008 Icy Blue Mazda CX7
Stock engine and exhaust (YES!!), JBR3" + GTX2867 gen2 + Autotech HPFP, self-tuned to 330-ish BHP
Stinow
Posts: 14
Joined: December 19th, 2022, 2:13 am

Re: EGR P0401 insufficient flow after flashing Base US93/EU98 map

Post by Stinow »

Maxl wrote: May 29th, 2022, 5:39 am Hello,

I had the same error after installing versatune. I also thought it was coincidence. Then later I installed a egr block off plate and disabled the error. Now because of other reason I removed Versatune from my car but I let the block off plate installed and I don't get any errors. I don't know why but maybe something is different to the software of US to Europe Mazdas...

I also noticed a little different cold start processing between oem software and versatune but that's an other topic...
Hi Maxl!

Same here; egr P0401 about 90 km after installing Versatune with a tune. Tried cleaning the EGR, but not fixed yet.
Also same difference in cold start ;)
Maxl
Posts: 10
Joined: January 8th, 2021, 1:05 pm
Location: Germany

Re: EGR P0401 insufficient flow after flashing Base US93/EU98 map

Post by Maxl »

Hi,

After Removing Versatune and later Installing it again the error didn't appear again .. :?:

And I don't know why the Coldstart is different with Versatune / US Software compared to my OEM Software, maybe its something about emission... :)

Greets
mituc
VersaTuner guru
Posts: 1324
Joined: December 17th, 2011, 2:47 pm
Location: Iasi/Romania

Re: EGR P0401 insufficient flow after flashing Base US93/EU98 map

Post by mituc »

Maxl wrote: January 22nd, 2023, 8:54 am And I don't know why the Coldstart is different with Versatune
How is it different?
2008 Cosmic Blue Mazda 3MPS
Built engine + WMI + GTX3071 gen2, ~509BHP @34PSI
2008 Icy Blue Mazda CX7
Stock engine and exhaust (YES!!), JBR3" + GTX2867 gen2 + Autotech HPFP, self-tuned to 330-ish BHP
Maxl
Posts: 10
Joined: January 8th, 2021, 1:05 pm
Location: Germany

Re: EGR P0401 insufficient flow after flashing Base US93/EU98 map

Post by Maxl »

It's not a big difference but I try to describe:

My OEM:
The engine revs exact to 2000u/min and stay there for a couple of seconds and than slowly go down

With Versatune:
The engine revs a little bit over 2000 (~2100) stay there for some seconds (but I think a little bit less than OEM) and than slowly go down.

All at summer temperatures. I know it's not a big difference but it looks much better when the engine revs exact to 2000 instead random over 2000... :-D
mituc
VersaTuner guru
Posts: 1324
Joined: December 17th, 2011, 2:47 pm
Location: Iasi/Romania

Re: EGR P0401 insufficient flow after flashing Base US93/EU98 map

Post by mituc »

By default the OTS tunes do not alter the idle RPM, and the engine start code is not touched by VT. I've not had any cold start RPM differences between OEM and VT and I'm using VT for more than 10 years now. Since recently (2019+ ?) there were some issues with the engine sound (sounds rougher at cold starts), but no change otherwise.
If you cleaned the throttle body more than 3 years ago I suggest to go back and clean it again.
2008 Cosmic Blue Mazda 3MPS
Built engine + WMI + GTX3071 gen2, ~509BHP @34PSI
2008 Icy Blue Mazda CX7
Stock engine and exhaust (YES!!), JBR3" + GTX2867 gen2 + Autotech HPFP, self-tuned to 330-ish BHP
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