Hi Scoobynet

My Impreza GC8 from 98 has been running stock boost (0.95bar) up until now. It runs fine - but when I raise boost to 1bar with an MBC, it starts hesitating and idling rough. Sometimes it'll cut out. If I let it sit overnight, it'll be fine the day after, until I hit 1 bar again.

It's running NGK 6 spark plugs - could this be a symptom of this plug being too hot for the new boost level, or does it sound like a totally different problem?

Current mods are:
1 bar through mbc
Downpipe with sports cat
Sports catless from dp
Simota panel filter, silicone hoses
Walbro fuel pump

 

so you upped the boost, played around with the exhaust, changed the fuel pump, didn't have it mapped and wondering why its driving like a bag of spanners?

 

No it has been running fine, and I know several people with a similar setup (no remap) on a gc8 that run fine. The old classics seem a little more forgiving.

I'd just like to have everything in order (spark plugs etc.) before a remap.

 

Best of luck, bud.

 

It needs a remap, simple.

 

If that's all it needs, I'll just go for it - I just wanted to make sure nothing else was an issue before taking the step. Thanks.

 

Again...best of luck. The 98 ecu isn't remappable.

 

Exactly: I'll need a different ecu, hence my wish to minimize risks before this expensive operation.

Since you all advise me to just do it with the same std. spark plugs and everything, I may be overthinking the "prepping stage".

 

for the price of em chuck some 7's in instead of 6's to make sure.

 

plug gap ?