Technical P1171 Fault Code Tjet Punto

[Specs43]

Well Lads,

Having an ongoing issue with my 2008 Tjet punto, I am getting a p1171 fault code along with what seems like limp mode. The car is down on power and is running lower boost than it should, If you delete the fault codes the car is back to full power for a day then eml is back and power gone. I have scanned the car with a decent scan tool and I I am getting a P1171 code along with the message : Additive adaption correction of lamba - circuit voltage below threshold : I cannot decipher what this means. I have read a few threads on this and they seem to not have a conclusion to this issue. I have read of people replacing sensor after sensor to no avail. Along with the limp mode, I have a somewhat poor idle which is getting progressively worse, to the point were the car is dropping to 400 rpm or less then jumping back up. This may be unrelated but it may help. I am wondering if this is injector related? Or maybe lamba sensor. The car does not seem to be running rich or be any worse on fuel.

Has anyone came across this, And if so what was your fix. Any help would be greatly appreciated.

 

[owengill97]

Check all your vacuum lines for the turbo and at the back of the engine where the diverter valve is , when my tjet was going into limp mode the vacuum lines were split. Also on standard turbo when it was mapped it cracked the turbo housing inside in the same place twice on separate turbos. Where the wastegate opens inside it was cracked. After upgrading vacuum lines an a bigger turbo my limp mode has completely gone.

 

[Specs43]

Good to know, I have check the vac lines on the turbo, But not at the rear of the engine.
I was kinda thinking that it may be down to a crack on the turbo somewhere, as I know these IHIs are known for it.
Thanks for that, I am going to check the vac lines right now.

 

[owengill97]

Good to know, I have check the vac lines on the turbo, But not at the rear of the engine.
I was kinda thinking that it may be down to a crack on the turbo somewhere, as I know these IHIs are known for it.
Thanks for that, I am going to check the vac lines right now.

No worries let us know how it goes

 

[Specs43]

Checked vac lines, all seem perfect.

 

[owengill97]

Checked vac lines, all seem perfect.

Just found a page of MES highly recommended buying if you haven't got already. Looks like it's worth testing your injectors

 

[Specs43]

Thanks for that Owen, I have heard if MES before, This list is very helpful. I am looking towards injector issue, I am bringing the car to a friend of mine soon who is a master diagnostic tech for VW, hopefully he can shed some light on it, The car is going in for its NCT (irish mot) today. I will knock the light of and go from there, I will update as I go along.

 

[owengill97]

Thanks for that Owen, I have heard if MES before, This list is very helpful. I am looking towards injector issue, I am bringing the car to a friend of mine soon who is a master diagnostic tech for VW, hopefully he can shed some light on it, The car is going in for its NCT (irish mot) today. I will knock the light of and go from there, I will update as I go along.

Keep the thread updated, would like to know the fix if I ever see this code myself

 

[Specs43]

Issue Fixed
Turn out to be a leaking PCV diaphragm, My VW master tech figured it out in 5 minutes, he figured the poor idle was due unmetered air and the PCV leak allowing to much air in the intake, and that this also caused my engine light, he squeezed the pipe coming from the back of the PCV into the intake manifold, as soon as he did the cars idle settled. We then plug the pipe with a bolt and deleted the codes. The car is now flying and I can finally enjoy the 170 bhp the I never got to experience properly. Thanks for you help Owen!

 

[owengill97]

Issue Fixed
Turn out to be a leaking PCV diaphragm, My VW master tech figured it out in 5 minutes, he figured the poor idle was due unmetered air and the PCV leak allowing to much air in the intake, and that this also caused my engine light, he squeezed the pipe coming from the back of the PCV into the intake manifold, as soon as he did the cars idle settled. We then plug the pipe with a bolt and deleted the codes. The car is now flying and I can finally enjoy the 170 bhp the I never got to experience properly. Thanks for you help Owen!

Great to hear that! Il keep it mind for my little tjet too