Hey all

Got a straight through system on my imported 93 wrx with just an apexi backbox. 2.5 inch system and a HKS 3 inch down pipe. Sounds bloody ace but when u give it some, at higher revs it holds back a hell of a lot like its stuttering. all of the engine a.o.k and it only does it when i de-cat, when the cat goes back on its fine. any ideas why? does the ecu have to learn or what?

Hope someone can shed some light on this

Cheers

Tim

 

try resetting your ecu .

i had the same prob with mine

 

Always a good idea after mods. Especially if she is running poorly now.

 

thx for the replies guys, i will reset the ecu to start off with and see how it goes. other than that it will have to wait till i jap innovations for me blitz boost controller and HKS fuel cut defender, hopefully they will help if the reset doesnt.

Thanks again
Tim

 

dont forget the knocklink m8 and a AFR meter would be nice,just so u know things are running ok in the fueling department.

 

Thx mr smash, i have got a knock sensor and all is a.o.k in that department, afr is on the list to get. I also bought a walbro fuel pump which runs great in it, sounds much healthier than the standard one i had in their! so fuels definately getting there!
As luck would have it the car is off the road at the moment as im saving for a respray and a few little extras before i put her back on the road!

 

Whoa there, just count to ten before you do anything.

Strongly suggest that fitting these extra gadgets before finding and curing the problem isn't the cleverest course of action. Could be overboost, could be det, could be something else altogether, but either way raising your boost and fuel cut levels on an engine that is already obviously unhappy is a route more likely than anything else to end in tears.

Even in a best case scenario the extra gubbins will make the source of the problem more difficult to isolate, so sorting it first would be a good move all round. Take it your KnockLink doesn't register any unusual engine noises when things start playing up?

 

Agree with GM there. There's absolutely no point fitting enhancing parts to your car unless it is running right in the first place.

We (JI) would not fit such products to a car unless it is running correctly to start with.

I'd hazard a guess and say you've got a plug or coil pack problem there and the fitment/non fitment of the cat is a red herring. The last thing it should do with a decat is "hold back" as opposed to with the cat in. It could be overboosting perhaps (what is is boosting to?), although I doubt it as the symptoms would be more like "hitting a brick wall" than "holding back and stuttering"

An ECU reset would be a good idea though after mods.

Suspect the problem lies elsewhere.

Check your coilpacks first.

Rich