I have a problem with my 97 WRX. The history over the past week of the car has been that while in the north island (im from CHCH) I only used 98 octane petrol from BP in Wellington (about four tanks worth during my visit). Also while in the north island I needed an exhast repair...so....while have the tail pipe repaired the guys at Pit Stop noted that I had a CAT still installed and suggested that i have it removed. Okay I said, no problem.

Great...the car has been running fine (about a week and 700km's on 98 octane). Until yesterday when I needed petrol (note that only 96 octane is available in the south island). I put $10 in and while in the motorway at about 80km/h in 4th I accelerated fully and the engine cut out and about 4000rpm, I then tried again, same thing at about 3700. I have reset the ECU incase of the octane rating being an issue and nothing has changed.

What is the problem here???. During a few test runs the car can accelerate fine unless the turbo is being fully used. I noted that the boost gauge when it peaked at about 1.1 kg/cm (about 15.6 psi) the engine cut out (i think the boost used to peak at about 0.9 kg/cm before CAT removal), you can accelerate furthur as long as you dont go over about 1.0 kg/cm of pressure. I have no way of manually changing the boost and have never changed anything on the car until the CAT removal. What has caused this, was it the change in octane rating or because of the CAT removal (although that worked fine for about a week). Any ideas or good places to get it checked out in CHCH.

Also. I have used that first $10 of gas and refilled at another station to eliminate any fuel contamitation issues from the first station.

sounds like the CAT removal is causing boost to spike on wide open throttle, this spike is obviously higher than the fuel cut limit and therefore your cut out is coming in.

How to cure depends on how much money you want to spend. Whether it's CAT back on, re-map, decent electronic boost controller, etc

I used a Dawes to reduce the max boost to below fuel cut-works fine and no spikes.

Les:)

or buy a fuel cut raiser, but make sure you know whats going on i.e detonation and boost pressure...

Dan:D

Yes try Crowesport, probably the best in CHCH

Agree with jameswrx on the cause... A $5 restrictor would be the cheapest way of fixing it...

In CHCH I would talk to Stewie Weeber at Stubaru on 03 366 9044...

I have had the car looked at by a turbo place and they have said that because of the 3" piping there is not enough back pressure being created and they suggested that I have the wastegate bored a little???? According to them, is a relativly common problem with 3" piping. Even if that was the case why has the car worked fine for a week in that config? Anyone else had problems with that size of pipe? Also, I have checked vacumn/pressure lines and all looks good and wastegate actuator tested out alright. Maybe solinoid, How do you test that?

My car has also got a 3" system with one free flow cat. This caused the increase in boost as Jameswrx says which went just beyond the fuel cut. Using the Dawes to reduce the max boost to 1.05 bar/15.22 psi stopped the fuel cut. As Dhorwich says, you could also use a fuel cut raiser to get rid of the fuel cut at a higher boost figure. Might be unwise though if you can only get 96 RON fuel on the South Island. I would not want to mess about with the wastegate though-irreversable mods can be trouble.
Les:)

[Edited by Leslie - 7/14/2003 4:09:00 PM]