I'm sure that oil is fine for your car aslong as its not castrol edge.
Honestly I'd either use penrite if your on a budget or if you want the best use royal purple did wonders for my car and had test results to back it up. Or use something similar Mobil 1 martini racing oil is also good but you will have to order it online.

But I would get you car to a dyno ASAP
If its a full standalone as what it sounds like it is
If it Is badly out it may cost you quite a lot to be retuned.. But
First thing get software that works so you can at least pull codes from it

Secondly get a decent tuner to see what the go is.

Depending where your from someone can recommend a good place to go.

Best of luck.

There is a place just 2 minutes from where I live, and I know that he has tuned 3SGTE engines before because I seen an ST165 Celica in there.

I was going to buy Royal Purple but Super Cheap had a sale on oil and oil filters the other day and don't sell it so I bought penrite, but havn't put it in yet. Might put it in just before the tune.

I have the software on a laptop that came with the car, but the laptop won't turn on.

I'm in Wollongong, any recommendations for a tuner?

Not sure someone closer can help you out
What kind of penrite did you buy? 10 tenthts is really good
Other then that I wouldn't use anything else but 10 tenths racing or the hpr one
I tend to opt for performance oil that has proven results I listed a thread on here about oils try and find it

Type in the search bar the end result of a test on performance oil

The article was called the truth about oils
I use that I use 10-40 royal purple.
And for the track recently used 10 tenths racing 10-60 penrite that was really good aswell.

But I'm changing to martini racing oil as heaps of guys use it and rave about it so I'm going to give it ago ill update the thread once I've tried it.

Interms of tuners not sure
There's quite a few good ones in Sydney if you want to drive there
Maybe someone else can point you in the right direction.

I would get the laptop fixed or borrow someone else's laptop and hook your car up and see if its throwing any codes as just for a tuners to check for codes will be most likely 50-100$ work and he hasn't even fixed anything yet.
So I would do that myself
Could be as little as a dodgy O2 sensor.

Once all codes are cleared if there are any and you have fixed the issues from the codes and it still hasn't really helped
I would then take it to a GOOD tuner who knows what he is doing with
The car and the ecu
Many tuners only mess with one or two types of ecus a guy up in Newcastle will only specialise in apexi systems
And my partners uncle who owns a shop only touches haltecs and does a mighty fine job with those.

So make sure he knows what he is doing other wise he may do more damage then before you took it to him.

I would talk to some of the more experiences guys like
Toten
Just ace
3sge turbo
Etc all these guys know there stuff

I got the 10 Tenths oil.

Maybe I should do a search on here for a thread on good tuners or start one myself.

Yeah sweet
Good plan :)

Ant1
 I even raced my mates modified R33 Skyline yesterday and beat it.

there's your problem :P

Why? Because I raced? Lol

Ant1

Why? Because I raced? Lol

no just all the 'races' before than one i'm worried about... 

You need to have the aftermarket ecu tuned/checked as soon as possible. Your asking for engine trouble racing people, thrashing it etc when it is known that the current tune is no good.
If it was me I would have been driving the car like a grandma as soon as I picked it up from the seller. First thing would of been a service (oil, oil filter, plugs, cap, rotor etc) then to do the dyno to check the tune before driving it hard.
 

^thank you Mrskylighter, EXACTLY what i was trying to say without actually saying it lol