lumpy idle and poor fuel consumption - maf/egr codes?

[samjac68]

hi guys. just wondering if i could get a bit of advice on this one...

ive recently bought a mk5 GT Tdi 140ps. it has an engine management light on and its pretty poor on fuel and has a real lumpy idle.

plugged into it with a solus and got, mass air flow - implausible signal and egr not flowing. if i reset it it will stay off and the idle seems better until the light and 'emissions control' flashes up after 30 miles or so.

the mpg seems to show 20-30mpg around town. if i put fuel in itll come up 100 miles and itll seem to reduce 5 miles on the computer for every 2 miles you do

the only other thing is it does have a slightly leaky boost pipe coming off the driver side of the intercooler (just hisses a bit)

so my question is, is this the egr, maf, boost pipe or something else? i know the maf monitors the egr so im not sure which way to go with it?

thanks all

sam

[th3_f15t]

Go the cheapest first and work through the sensors and pipes. I would change that boost pipe straight away as you don't want to risk dirt and other nasties going into your turbo/engine.

[Rhyso]

Fix the problem of the leaky boost pipe and go from there. You'll be surprised at how much it can affect performance

Then clean out the EGR valve