Help! cant pass mot on emissions!
 

In need of serious help in a hurry here, I have a 95 wrx I'm trying to get through its mot, and its emissions are through the roof! I've fitted a pretty stock exhaust with plenty of cats and silencers in and its still miles over, I've no idea how to get it down! I've got its original z4 ecu, and one that says prodrive on and looks pretty custom, the z4 gets it closer but is still somewhere in the 2/3 times the limit region. Help!

Sounds like you need a new lambda sensor or get the cat red hot before the test ...

When was the date of 1st registration if it's 31st July 1995 or older if will need only a non cat test,if it's 01st august 1995 then it will need to meet cat default limits..I'm a mot tester . There will be no exact match in the mot testers database as they didn't list any till 1996 and those were uk not wrx version.

Lambda sensor solved that for me a couple of years ago. One garage started banging on about needing a new cat etc but once it was put on diagnostic computer it was just the lambda.

Cheers for the replys, I've got a check engine light coming up on the dash suddenly, can i use the old bridge something under the dash and read the morse code method on my 95, or is it too old? I'm pretty new with subies, aren't there two lambdas in these? I've also pulled that page on an MOT tester in the past with my starlet gt and he produced some counter bull**** paper that said i still had to meet some other emissions. the engine in the gt was never sold in the uk at all!

Thanks!

if yours was registered before 31st july 95 and tester refuses to peform non cat test then say your going to contact dvsa(vosa).

Dvla just says it was registered something 04, presumably when it was imported.

the code flashing up on the dashboard is 22, knock sensor. a bit of looking around seems to match the symptoms to this so ill change it and see what happens!

Don't forget to reset the ECU after you replace it.

I still have a problem here, i replaced the knock sensor and reset the ecu, which made it run better and brought its emissions down from 6.5 down to 0.6, but it needs to be under 0.2 to pass and the ecu isnt reading any more faults so i dont really know where to look any more. It breaks up under any boost, really doesnt like boost at all if that helps? Just hoping someone here knows what might be wrong!

1st I would be checking is all the turbo pipe work,all connected ok? Any splits/cracks(old pipes can get brittle) Very common problems with boost can often be faulty boost/vac lines

That reminds me, theres a vaccum hose coming off the throttlebody that just blanked off, ive no ida where its supposed to go to, so ive no idea if the other end is blocked off!

Sounds like your boost solenoid is bypassed.

No, my boost solenoid is all still plumbed in. i've got it so close now, ive cleaned the MAF and blocked up some holes in the intake that shouldn't be there and its now 0.36 odd, but i cant quite get it any lower. ecu doesnt bring anything up, im outta ideas. any suggestions?