Hi everyone just trying to get bit of information. What's the best oil/oil filter to use on 2004 WRX. Also i am needing to change my CAT due to failed emissions is it true that a Subaru exhaust system has 3 cats if so is there anyway of knowing which one needs replacing? Thanks in advance.

 

Gentlemen on here from http://www.opieoils.co.uk/ has always sorted me out

 

You have 3 cats yeh, a precat in the up pipe, main cat in the down pipe and a cat in the centre. Do you have any fault codes stored at all? Id be checking the rest of the exhaust is 100% not leaking anywhere first, as that would be another cause for failed emissions.

 

I would say,your O2 sensor/Lambda sensor fail and this will cause problems....




Jura

 

you can remove the second cat and still pass an mot so its usually the cat in the downpipe. as said check all the exhaust for leaks etc

As for oil 10w40 fully synthetic esther based oil. Ones ive listed below are all good oils
MOTUL
FUCHS
MILLERS

And only use genuine o2 sensors if they are faulty as even new ones can throw up codes if not genuine

 

Hi mate on the cat are you sure the test station got the cat hot enough? when i test then we have to get the cat stinkin hot before we do test and have no prob you can also put a can of catoclean in the fuel a run it that makes a diffence. As oil and filter the blue oe filter have got a bad name on the forums so I guess any good named filter will do. As oil i use 10/60

 

This'll start a war! LOL.
a 60 weight oil is too thick. When you consider in my manual it says 5w30 or 5w40, most garages will move to a 10w50 at most.
Like I say, each to thier own I say!

 

The blue oe filter has been replaced by a black one now anyway, the blue one is no longer available and the black ones are fine as are any good quality filter such as ADL Blueprint which are available on my site www.j-autos.com

As for 10/60 that would be fine if you buget in for an engine rebuild also lol. Strongly advice against that. stick with 10/40 fully as mentioned before. or 10/50 at a push maybe but its personal choice i guess.

 

If been remapped above 250BHP 10/60 Fully Synth all the time.On my fifth Impreza and never had any problems (unlike a lot of members running big BHP with bottom ends letting go).Try Lucas 10/60 Full Synth been useing this oil for past three years fantastic oil and also comes in 5 litres containers,use in conjuction with Blueprint filters leave the Subaru nasty ones on the shelf where they belong.

 

good news about subaru bringing the black filters back in, but if your local dealer hasn't got them yet or something, then i would buy a k and n oil filter, someone did a write up on here, they are good quality. about oil, i would go with a 10w/40 or if you want/high stage of tune, a 10w/50.