BOOST COMES AND GOES PLEASE HELP MK5 GOLF GTI

[Matt_hutton1]

Hi a newbie here,

I have an mk5 golf gti and all of a sudden its lost all boost and mpg was around 8-10mpg the car still drives fine just no boost and no lights on dash, first thing I did was changed the diverter valve and works for a few days, I managed to get it plugged in and got the code P2177 (system to lean off idle, upper limit exceeded) but no lights on dash. I started with the basic I took my maf sensor off and cleaned it and put some shell nitro fuel in and it worked boost was back and was all good for a few days now its gone again. I cleaned the maf again and now its stopped boosting again so gonna try a new maf sensor do anyone else have an ideal what to check?? the induction kit and boost pipes are all fine aswell


mk5 golf gti
backbox delete
resonate delete
pcv delete
ram air induction kit
gfb dv+

[pudding]

That error suggests a big ol air leak somewhere.  Check are the O rings in the boost pipes, look for sweaty oil patches on the intercooler and other connections.  They are a big pain in the arse and upgrading to an S3/6R intercooler at some stage deletes 2 of them.

What PCV delete have you got?  The R tech one that just dumps out the cam cover to atmosphere and blocks off the front one?

Backbox and resonator delete?  Jesus that must be loud 

[amanda]

I would also be checking all black rubber for any splits!!!

[Matt_hutton1]

I got an MTC AUTOMOTIVE pcv delete and ok ill check them. To be honest with both deleted its not to bad still pretty quiet on tickover and pops good aswell