boost issues (No get up and go)

[chads77]

hi. any help or advice is greatly appreciated
so my lcr still has a distinct lack of boost...! I have changed all coil pack and plugs. removed pcv and fitted catch can. New maf. New n75
replaced all the vacumm hoses to silicone to eliminate any boost leaks
I am at a total loss now with what could be causing this although a brief chat with a friend said maybe n249 issue....? What do you guys think if this is a faulty unit can the bypass be done to eliminate this or do I need new.!

 

[Yorkshireboxer]

N249 can be bypassed seatcupra.net/forums/showthread.php?t=349627 this link should help hope you manage to sort your problem

-Rob


Sent from my iPhone using Tapatalk

 

[chads77]

Cheers Rob I'll give it a try over the weekend....! just can't think of anything that it could be...!

 

[Yorkshireboxer]

Not a problem if it works let us know if not I'm sure me or another forum member will be able to help

Happy tinkering

-Rob


Sent from my iPhone using Tapatalk

 

[ibizacupra]

vcds logging may show something..
without that or dyno logging you are chasing the wind

 

[chads77]

So had the car in garage today still none the wiser car was showing p0171 fault code. had throttle body cleaned and realigned etc.! still same with lack of boost... garage said poss 02 sensor Would this be a likely cause...?? any help appreciated as CARS TURNING INTO A CASH COW I'm running out of patience/money please help

 

[ibizacupra]

take it to a specialist

 

[chads77]

hi bill
thanks for your reply. The garage is a vag specialist and been on there vag diagnostics.. but coz the car is mapped they've said they had trouble reading parameters and said possible 02 sensor is no good and start with changing that...! was just askin if this will cause the issues coz I've changed all the plugs coil packs pcv system replaced with catch can new n75 valve and vac hoses for silicone items and still the symptoms persist and everything I've read on here and the net still says boost leak but garage have ruled this out..! There telling me it's the 02 so probs gonna have that changed but if that's no good where do I go from this as there a vag specialist and telling me it could be the 02 sensor...! seems these cars are a pain in the bum to diagnose thanks again

 

[Bouncerbeater]

Wouldn't have thought O2 sensor problem would give a lack of boost, well not in my experience anyway. Have had an ongoing long term problem with front O2 sensor giving intermittent fault but never experienced lower boost at all. Always has gone great regardless.

 

[ibizacupra]

hi bill
thanks for your reply. The garage is a vag specialist and been on there vag diagnostics.. but coz the car is mapped they've said they had trouble reading parameters and said possible 02 sensor is no good and start with changing that...! was just askin if this will cause the issues coz I've changed all the plugs coil packs pcv system replaced with catch can new n75 valve and vac hoses for silicone items and still the symptoms persist and everything I've read on here and the net still says boost leak but garage have ruled this out..! There telling me it's the 02 so probs gonna have that changed but if that's no good where do I go from this as there a vag specialist and telling me it could be the 02 sensor...! seems these cars are a pain in the bum to diagnose thanks again

unlikely to be 02 effecting boost..
post cat one?

 

[chads77]

yh the 02 sensor after the cat they've said at the garage..?
However car has behaved as a cupra r should for most of the day on a few 4-5 mile journeys today car has been brilliant....? however somewhere on a 12 plus miles motorway journey on my way home car went into a limp mode ? slow/reduced power. but no management lights on...! parked car up and left it till now...! literally just been back out to the supermarket 3 miles each way car behaved brilliantly again....!!!
I really don't understand this car lol....
again is there anything I could check..? is this a temperature thing?
again any help is greatly appreciated

 

[ibizacupra]

check logged codes

 

[verbal_kint]

I would also say find another specialist for a second opinion. There are specialists that just call themselves that, then they are specialists that warrant that title.

A faulty o2 will generally affect mixture ratios to try to maintain the correct mix, a check on the plugs is an easy way to show lean or rich running problems.

You could also drop a friendly MOT station (the ones that only do MOT's are generally good for that) a tenner to just do an emissions test, if that is fine then your O2 is good.

Edit: reading thread again I see you mention code P01701 which is a lean running issue often caused by MAF sensor. That can be checked for good working before blindly replacing I believe.

 

[chads77]

Hi car behaved well till Sunday night but.had issues again. Had car scanned on a snapon scanner local to work and fault code of 17705
Cleared code restarted car fault code straight back on but again not showing any eml lights. Had another poke around under the bonnet and found a slight slither of clean oil on the T.I.P just after it Jubilee's on the turbo and inbetween upwards elbow if that's described correctly... And again with a lack of power/performance.

 

[yorkturbo]

Just had same issue with mine changed throttle body throttle position sensor maf when up road no better unplugged maf runs like new try running with it unplugged????