Mk7 running problem

[botzz]

Morning all! Hopefully someone can point me in the right direction, I've a mk7 2010 2.4td transit 140hp, while driving can be fine, then sometimes almost seems flat/ unresponsive, I've got a stainless steel system fitted, so not only do i notice the van seems slow, the exhaust tone changes! Also kicking out abit of black smoke, If I turn the van off then back on, things seem to go back to normal, but it doesn't always seem to want to start straight up, any advice or someone to go to Doncaster/ surrounding would be great cheers liam

[motorman116]

More than likely the EGR valve....

[botzz]

Cheers motorman I'll have it checked out

[knobby1]

Agree with Motorman...have you had codes read??

Lord Knobrot

[botzz]

It's only just started doing it, but it's intermitent, and no dash lights have came on! Although I'm going to book it this week to see if it brings anything up, cheers liam

[botzz]

Bit of an update, I've had egr turned off, my problems have gone thankfully, cheers for the info