Help limp mode P0401

[ad01]

hi

was having a look at the engine bay today , and i noticed the thin black and blue pipe was off the egr valve and blocked off using a screw

and ideas

thanks
as always

[crystalworks]

Replace the vacuum lines and go from there?

[ad01]

i did exactly that and still goes in limp mode

[crystalworks]

Ever replaced the EGR valve before? How much mileage is on the vehicle. M57 diesel I presume?

[upallnight]

Previous Mod by a Previous Owner. See if you can search this mod on Google.

[wpoll]

Originally Posted by ad01

hi

was having a look at the engine bay today , and i noticed the thin black and blue pipe was off the egr valve and blocked off using a screw

and ideas

thanks
as always

Well, that's the cause of the EGR code (the P0401)....

Just putting the vacuum hose back won't clear the code - you need to erase to code with your scanner. But I'm not convinced that this is causing the limp mode, although it is possble (in conjunction with other errors we don't yet now about).

Looks like the previous owner was a real butcher...

[ad01]

what i don't understand some days it drives absolutely brilliant pure power and performance ... and then some days it goes in to limp mode

the last owner was an idiot blocked and bypassed a thew things , maybe there is something i,m missing why he blocked and bypassed pipes is beyond my ability to understand

[ad01]

i think ive found the problem

i unplug mass air flow sensor when engine running and it didnt die

went for a good drive with out the sensor plugged in to see any power loss and guess what no power loss what so ever and no limp mode ??????

what you think

[Fifty150hs]

Originally Posted by ad01

i think ive found the problem

i unplug mass air flow sensor when engine running and it didnt die

went for a good drive with out the sensor plugged in to see any power loss and guess what no power loss what so ever and no limp mode ??????

what you think

Bad MAF

[wpoll]

Originally Posted by ad01

i think ive found the problem

i unplug mass air flow sensor when engine running and it didnt die

went for a good drive with out the sensor plugged in to see any power loss and guess what no power loss what so ever and no limp mode ??????

what you think

Plug the MAF back in and if the power loss and limp mode return, then it does indeed sound like a bad MAF.

When/if you replace it, change the air filter and engine breather while you're in there (access is a difficult so you might as well replace these items while you're in there) and also use a genuine MAF - the aftermarket ones are rumored to give trouble.