It must be maf sensor

Whenever the car goes out on a long drive and in damp weather it coughs and splutters the next day and maybe the next and I'm thinking the only way to cure it is to get a caik to stop the sensor getting hammered or a new sensor is required.

Could it something else? Just seems to happen everytime after a long drive and goes after a day or two it goes away!

Any thoughts

To be honest mate I've never had to replace a maf on a hatch yet
I'd be surprised if that's what it is.

I'd be doing some checks on the engine readings and graphing it first, However I have seen some of the secondary air pump valves jam open and cause similar symptoms.

any other symptoms ??

It's all a bit strange and I can only logically put it down to maf sensor. Unless it's poor fuel quality which it could also well be. Filled up with momentum 99. Is the engine that sensitive to fuel quality?

The other symptoms are quite bad hesitation in the rev range. It's funny as it goes as quick as it arrived?

When I went out last it was a long drive and extremely extremely wet and it has seemed to take longer to go! The car has done this since I have had the car and until recently I have just put it down to fuel. Have had it checked once by Subaru

Have taken it to Subaru for a check up as it has done this off and on since i have had the car and asked them to check for piston roughness but they said it all checked out fine. not convinced I didn't ask for any print outs etc. It has had a short block at 16000 it is now at 26000 so 10 on new block. Maybe dealership didn't do a proper job on rebuild?

More I'm thinking about it now the more I'm thinking it could be momentum 99 which is the problem as it has arisen out of nowhere previously after using half a tank of it

Will now keep on v power and see how it goes

always ran ours on momentum 99 never had a problem with it , what your describing sounds like what I got when rob put ours back onto the standard airbox etc from the aem intake ! .
Went very sluggish / hessitant afterwards !

Mines does the exact same to the systems you described:

Hesitation
Juddering
Taking longer too spool up
Sometime feels like not getting all the power.

But then it goes away.

I have had it checked out no issues to report, thought it may be fuel quality but ran the tank right down filled at more reputable shell stations still the same.

P4UL wrote:Mines does the exact same to the systems you described:

Hesitation
Juddering
Taking longer too spool up
Sometime feels like not getting all the power.

But then it goes away.

I have had it checked out no issues to report, thought it may be fuel quality but ran the tank right down filled at more reputable shell stations still the same.

those are perfect symptoms of early ringland failure. a compression & leakdown test would Identify this. I bet if you reset the ecu it would be fine for one day then go back the same again

Well I had thought this initially, but It has been doing this for 15000miles & doesn't use a drop of oil either, plus it gets driven pretty hard alot of the time.

In a bit of a drama what to do with the car the now anyway as my family is expanding, so thinking of trading it in against a forester as I quite like them and buy a track toy