My current zorst is a cobra bellmouth sports cat 3" mated to a 2.5 magnex cat back but,iv been offered a 3"decat turbo back .the scoobs a my97 UK turbo with minor mods ( sti tmic and panel filter ) mapped with mafles esl .
iv seen quite a few classics running decat without being mapped ,but is that a risk or will the standard ecu compensate for the lack of cat ?

 

Been running a decat unmapped for nearly 3 years with no issue

 

To be safe get it remapped, it'll be cheaper than a rebuild.

 

I have ran one for 11 years and 60 k miles

No issues whatsoever
Can fully serviced every year and goes well

 

What you're asking though is different to a standard impreza with a decat. It looks like you're asking whether you can swap a sports cat for a decat on a previously mapped impreza for specific mods? That I wouldn't do but I have run 3 standard classics with decats and no issues.

 

as above if its been mapped already,safer to get it checked after fitting

 

Cheers for the replies chaps

might just sell the toyosports turbo back then as i don't fancy being charged £100+ just to tweek a map .i just fancied a change( and my brother in law has just started doing mots at his garage ) im not after more power as the 380's and td04 will cap my figures anyways

 

I have run 2 classics with decat and both went pop(V3/V4 both STI), serviced every 4k miles with genuine oil filter and millers cfs oil, but they didnt last much, about 6 months and pop new engine needed, ,it could be me being unlucky with it but wouldn't risk now.IMO.

Map would be cheaper then engine rebuild.

 

As you have the freedom to get it tweaked, why not add some 440s and a td05 as well? That would be a cheap way to liberate alot more power. Add 20% meth on map 2 and you will have command of your very own rocketship.

 

Been doing it for over 4 years. Noticed it used to overboost when I first did it, so fitted a manual boost controller to cap it at 1.1bar. No boost spikes, no issues.

 

During the esl map my clutch started to slip so iv fitted a pink box which would handle the extra power but,i don't want my gearbox to spit it's dummy out .I have got a long term plan for the scooby to forge the v1sti cdb that's in my workshop but,i keep spending the funds elsewhere lol .Hence not wanting to spend to much on mapping but, my engines and box has gotta last till at least this time next yr till i can afford to complete the build (and a 6 speed) so i won't be taking the risk cos im generally not that lucky
thanks again for you input fellas
clive