new wrx sti owner

[machman]

hi all just purchased an 09 wrx sti hatch, having a few intermittent issues, been remapped by alan jeffry 370bhp.

sometimes it idles fine the its lumpy and revs rise a bit before dropping back.

also sometimes it will splutter on acceleration as if im in the wrong gear

im finding the car a tad complicated at the moment,there is no cel light or anything showing , i believe its possibly a sensor as its not all the time.

any advice gratefully appreciated

[stants]

Hello & welcome,

Have you run any diagnostics on it ?
Even though there's no cel could be something like an o2 sensor, it may have flashed up briefly then Dissapeared, the fault code would still be logged,

It really could be anything, may be best to get it on a dyno check for fueling etc,

Is it mapped for on specific brand of fuel ?

Has it always played up or more so now the weather is hotter?

Sent from my SM-G960F using Tapatalk

[machman]

only had the car a month.the only thing that showed up on diagnostic was rear 02 sensor as readings were eratic,which ive changed.was told could be a dodgy cat? always run on 98 octane was re mapped by previous owner.

[hackisfun]

On a completely stand engine 370bhp would be pushing the saftey limits. Also the standard injectors and/or fuel pump would be struggling.  A safe 370Bhp would have needed alot of money spend

http://www.scoobyclinic.com/performancetuning.htm

2.5 Impreza STi 2008 to 2011 Hatch

 

Performance Package 1	Price (all prices are +VAT)
Cat back quad exit exhaust fitted	£950.00
Package deal price	£950

Note: More a release of the Subaru signature burble than a power pack but its the first thing that needs addressing and not only does it make the car sound as it should in keeping with its character but it also adds 5 to 10 BHP free of charge.

 

Performance Package 2	Price (all prices are +VAT)
Same as Perfomance Package 1 plus:	£950
Sports cat fitted	£950
Re map	£550
Package deal price	£2,450

Approx. power figures: 330 BHP 360 FTLB

 

Performance Package 3	Price (all prices are +VAT)
Same as Perfomance Package 2 plus:	£2450.00
SC36 billet turocharger	£999
Cold air induction kit	£199.99
Perrin inlet pipe	£187.99
3 port boost solenoid	£99.99
Fuel injectors, ID 1000 cc	£440
Fuel Pressure Regulator	£275
Labour	£660
Package deal price	£5344

Approx. power figures: 370 BHP 375 FTLB

 

[savage bulldogs]

When was the last time the spark plugs were changed ?

As a o2 sensor fault could point to a misfire causing unburnt fuel to cause a spike in the afr ratio reading , rather than a faulty sensor and could be the cause of your symptoms 

[Jay762]

simple but also check for leaks - spray some carb cleaner on your pipe joints whilst idling if the revs rise you have a leak

[Guest]

On 7/6/2018 at 10:15 AM, stants said:

Hello & welcome,

Have you run any diagnostics on it ?
Even though there's no cel could be something like an o2 sensor, it may have flashed up briefly then Dissapeared, the fault code would still be logged,

It really could be anything, may be best to get it on a dyno check for fueling etc,

Is it mapped for on specific brand of fuel ?

Has it always played up or more so now the weather is hotter?

Sent from my SM-G960F using Tapatalk
 

I have a similar issue that seems to of gotten worse with the weather being hotter - is this an indication as to what the fault may be?

[Jay762]

It does sound like low down fuelling - warmer air = less dense.