Hi there,

Right so basically just bought my first Subaru wrx 2005 2L it has a prodrive map decat up and down pipes and a decat back box and basically occasionally it seems to cut fuel on high revs? I'm wondering if this is over boost or boost creep... I don't really know which Iv done some reading and haven't had a definitive answer? So my plan is to get a new external waste gate because it's standard, do you guys think this will fix it? Also will i need another map if I put one on.

Thanks guys
Ruairidh

 

Afaik the prodrive is mapped for sports cat not full decat,this could be your problem so may just need the wastegate duty tweaking to suit.

 

Ok thanks for that I'll read up and try that. Also this will sound stupid but is it a big job to do ?

 

You will need a tactrix cable to adjust any of the map.
If you head over to Romraider site there is a lot of good info.
There are also a few lads on here who are well up on open source mapping.
I've only ever mapped classics so not 100% sure if other cables will work on your car.
Has it got a factory prodrive ecu or has it been flashed by previous owner?

 

Where is Scotland are you? Probably best to get it on a RR to find out what's going on.

P.S. your turbo, if standard, will have an internal, not external waste gate. It may be a weak actuator your thinking of?

 

Ok I'll go check that out thanks man!

I'm in Aberdeen, where's RR?

 

Wallace performance might be your best bet.

Join scottishscoobies.com , you will get more "local" help on there

 

Also if I chuck on a diagnostic will it come up, sorry guys I'm really new to all this so I'm not really sure what it is, it's just like the fuel cuts out for a second then it goes again. Is this like really catastrophic for my car etc because that would be heart breaking haha

 

Ok I'll get on that tomorrow thanks for your help man!

 

I'm no expert mate but I had a similar issue with my classic many years ago and it was the MAF. Get someone local that knows what they are doing to check it.

Like I said mate, join scottish scoobies and ask on there. Plenty of guys from Aberdeen

 

Ok man I'll get on that in the morning thanks again!

 

Good luck mate and I hope you enjoy the scoob

 

If your not confident in remapping I would leave it to a pro mapper,as johnlogie suggests,that way you can make sure your running safe AFR,Timing Boost etc.
You can do your own datalogging with the correct lead and software but if you are unsure then it's advisable to leave it alone and take it to a pro.
I does sound like it's overboosting to fuel cut,do you have a boost gauge? What's it showing on full boost?

 

Split vac hose? Agree Rich that it sounds like overboost and a wee dyno session to see whats going on will do no harm for the relatively small cost. Will probably save the OP chasing his tail and causing potential long term damage

 

No I don't but a friend of mine was going to lend me his just to see if the boost was fluctuating. But is this like a turbo/engine blower, should I not be driving the car? It only dose it occasionally. The reason I ask is because as I said Iv just bought the car and I can't really afford to take it to anyone properly till i get paid. (Really worried)

 

I know this will be hard to do but keep it off boost and you "should" be ok

 

Ok thanks everyone who's replied to me so soon!

 

^^^this

Just to be safe then drive it steady until you can get it checked out.
Don't want to worry you but if someone has just flash mapped the prodrive map without proper checks then it wants looking at.
It could be just a simple pipe that's split or collapsing under boost,cheap silicone pipe and aftermarket intake pipes can do this.
It could be a number of things really and if it's detting on hard boost it could be the ECU pulling the timing back to try keep it safe.
Hope you get on ok,there might even be a kind member of one of the forums in Scotland who could plug it in for you and have a little check.
Or a cheap vagcom cable would allow you to datalog(it's pretty safe and easy to do) then you could have a look at your LTV which will tell you if things are healthy.

 

Hi guys, that's me booked into DMC preformace inverurie Aberdeenshire for next Thursday so fingers crossed they can help me. 300 for a diagnostic and map sound ok to you? Also gonna plug it into my mates diag see if It pops up any codes but heres hoping ill be ok.


Cheers
Ruairidh

 

Sounds ok to me

 

Hi there guys here's the latest,
Tonight I took it to my friends garage and we started having a proper look. There is definitely a whistle so we are thinking waste gate but we decided to try everything else first so we poped off the intercooler and done a smoke test... No leaks anywhere so that's good news. But from tonight's finds we have found there is a hole in the exhaust just before the first lamda so we are going to fix that on sat I also mentioned it seemed to use a lot of oil (I thought that was normal) so he's also going to do a compression test for me and do the waste gate at the same time. So here's hoping that solves it. He has also advised putting a car on a rolling road for diagnostics for over boost is a dangerous game thoughts? Also the worrying thing is if the compression comes back ok and he sorts the waste gate it I'm gonna have to give it some beans to see if it's sorted.

Thanks
Ruairidh

 

I was going to suggest boost leak but you've already done that. I had a similar issue a while back, at high revs/high speed the boost or fuel would cut and it felt like driving into a wall it was so sudden and forceful. Turns out the hose on the back of the intercooler was split, fitted a new hose and all was fine after.

Def recommend taking it to a rolling road to get the mapping checked out.

 

Yeh if the compression test comes back clear and he sorts the waste gate and exhaust ill take it in for a rolling just to see if its running ok or not. Iv heard having a hole right before the first lamda can throw the fuel too? hope this all sorts it.

 

the prodrive map is setup for standard cats on the WRX - the STI had the sports cat for PPP so by removing the cats on a WRX it's no wonder your seeing some fuel cut. Your doing the right thing now get it booked in somewhere to be checked over and mapped correctly for the mods on it - should drive like a different car when you get it back.

 

Ok cheers Ill let you guys Know how it goes!

 

Ok guys we think we have found the problem! So she's had her compression test and the turbo checked that came back fine (thank god haha) But what we have found is that the guys tried to make a home made decat by cutting into the cat and replacing it with a bit of pipe and rewelding it... This wouldn't be so bad if for 1 he could weld and seal it and 2 use the right sized pipe. So the reason it's over fueling is because there is holes all round his weld before the first lamda and it's the wrong sized pipe for the map so I am now on to looking for an exhaust system turbo back. If you guys have any recommendations I'd love to here them but I can't afford over 500ish for it. Thanks again for all the help.
Ruairidh

 

could you not get away with just the downpipe and use your current system ?

 

Yeh it looks like I'm going to get away with keeping the back box 😬 So my friend is a fabricator and he's gonna make me a mid section so all I need to by is a down pipe!
HAPPY DAYS

 

Hi again guys,

Right still having effing issues with fuel cut even tho exhaust is fixed now which I no means it needs a new map (Fml) right I'm not gonna have cash for this till the end of next month so I'm thinking ecu reset. Iv read a couple things online about this and I can see disconnecting the battery over night will do it. I'm not gonna do it though till you guys reply I dono if that's a really bad idea. So Bad move or not?

Thanks
Ruairidh

 

Also a friend made a very interesting observation that it only does it when turning, which I found interesting thoughts?