Comper100

Hi all

I'm fairly new to the scooby scene. I just wanted to know, having searched through loads of posts whether a standard EJ20 engine with few mods can pass and MOT (Friendy one) with the downpipe CAT removed as the i would like to reduced the lag and it seams like this is a good way of doing it according to many a thread. Also when doing this mod, is it worth opening up the turbo end of the downpipe to aid flow?

Next question, has anyone experienced problems with aftermarket panel air filters clogging up the air flow meter with excess oil, and is the best way to modify the standard airbox by removing the snorkel thing in the wing?

Thanks for any replys
Cheers

Comper100

911

The full decat will fail the emmissions by a bloody mile.
The panel filter to use for trouble free motoring is a Subaru/Sti/Green cotton make, go for the Sti IMHO.
Good luke with the Scooby World!

911

Comper100

Cheers

What happens if i leave the centre Cat in, and just take the downpipe one off, would that be ok?

What air filters come standard with STI ones then?

Thanks
Comper100

The_Judge

Some say that will pass, others say no. If your engine is operating as it should be, if the centre cat is in good condition, and is thoroughly warmed up just prior to the test, you stand a good chance of passing.

The well-known replacement downpipes will already have been "opened up"

Again, mixed opinions. I've always been led to believe the resonator is there for a reason, something to do with preventing water from getting into the induction tract/compressor/etc. But if you don't drive through deep fords, that may not be a concern. I'm not even sure removing it makes any difference to the cars performance. I think there's just more of an induction roar with it removed.

Nothing special. As 911 says, go for the STi. Although for a lightly modded car, you're not going to notice much difference between STi/Green/K&N/etc to be honest. Steer clear of the ITG though, if MAF contamination is a concern...


The Judge.

Comper100

Excellent, cheers for the advice chaps.

Comper100

Spenny_B

Ah, interesting...also a new Scooby owner, my car does have the ITG panel filter installed....can the MAF sensor be cleaned if mine is contaminated? Haven't yet delved under the bonnet too much (no time), can the MAF be easily seen, ie, checked to see if contaminated?

Cheers

Spen

Comper100

Thats what i was worried about, having a oil based filter and ruining the MAF, i suppose if you don't totally soak the filter in oil you should be ok.

The_Judge

The MAFs can be cleaned, but they're quite delicate, especially for the MY99/00. For the sake of £70, probably better just to replace it. Along with the ITG...

Spenny_B

OK, cheers Judge, will investigate...bugger really, as my mate who i bought the car from is an engine tuner (Vauxhall) and has very close links with ITG...he gave me a brand new one as a spare with the car...I've used them for years on my Westfield, but that uses throttle pot not a MAF....

Ta, Spen

ozzy

My 5yr old MY99 passed by a country mile with only the original centre cat. Mind you the cat only get's used once a year

Haven't needed to warm mine up and it even passed last time just stuffed on the end of my tailpipe with the probe in the other end.

Stefan

The_Judge

You must have very friendly people at your MOT station...! Wouldn't it be nice if the police had constabularies like that, who don't prosecute speeders if they brake at the time they're caught...