Hi folks,

Had bit of a problem today, took car to a friend who was unable to get it through the MoT as VOSA were present and watching.

It failed because of the emissions, and now am in bit of a pickle as it now needs a CAT which will fit onto a Miltek exhaust system,
which I have been told are not easy to find?

What are my options here please?

I have been told the options are a complete new system, which at the moment I don't have funds for, or friend is going to try and source complete
standard system to get it through the MoT.

Many Thanks

Marc

 

MOTS are getting harder and harder to pass even people with “mates” in the trade are dining it harder to get them through as they are just taking mot licence of testers now.
Yiur only legitament way of doing it is what your mate suggested or buying a cheap second hand cat and exhaust, the car scrap value is only about 50 quid and rest of it is just scrap have a look at breaking cars on eBay and have a ask.

my Impreza’s were always really good getting through emissions even with out a cat but they’ve changed it all now so you can’t work your way round the rev test,

 

Maybe you could take it back for a re-test when VOSA is not there?

 

Thankyou for your help, much appreciated, will look into it

Hi there, my friend said the re-test would still flag it up again, as it has already been recorded, not really sure what the rules are with a re-test?

 

Does anyone know if the Japspeed 200CPi sportscat will pass an MoT.

Its a reasonable price, and I can see if I can get it welded onto the existing Miltek exhaust
if I can't find a standard exhaust system.

Thankyou

 

Your exhaust should be in sections pal so just un bolt decat and fit cat.

Id say a sports cat will work there good on emissions and it’ll appear to have a cat on visual inspection.

 

Thanks for that, I think that might be the best and cheapest route, rather than take off the whole exhaust, just for the MoT
and refit the Miltek system back, will cost more in labour costs as well.

 

If I remember correctly from my miltek system they are a unique size so only miltek fits miltek,I may be wrong but something rings a bell.

 

Thanks for that mate, hmm, this could cause some problems then. I wonder how the decat was fitted to the Miltek system?

It doesn't look easy finding a Miltek sportscat, I may need an exhaust fabricator to weld on a Japspeed for me, think Miltek is 2.75 diameter.

 

Forget a retest go for a full test after your 10 working days you should start with a clean sheet as such then.

 

Thankyou for the heads up, I didn't know that information.

 

What model year is your car? Has it been modded/mapped? As if it has, the sports cat may not be enough to meet the emissions limit. If it hasn’t and you have a J-decat downpipe, I would buy one more and weld a standard cat in the second downpipe. Then all you have to do is swap downpipe come MOT time

 

Forgot to add to failure exhaust lambda reading after 2nd fast idle outside specified limits, have been
told front o2 sensor needs replacing also.

 

It's a 2.5 WRX 2006.

Yes, it has been modded with a forged engine, STi turbo fitted, STi intercooler, and was forged earlier this year. Remap done earlier this year by Bob Rawle.

Think I have got bit of a problem here.

 

Ugh, stuff like this makes me want to sell up and get a kit car instead.

My miltek is 2.75", but you could fit a standard downpipe and weld up an adaptor surely?

Alternatively, an exhaust fab shop can fit a 3" flange to the 2.75 tubing, so that you can bolt on a 3" section (this is basically what I have done).

 

It's possible to make the joints mate up to other brands If you've a milltek however theyon the catback system they make the different parts different lengths so they only really work with eachother unless you get creative. I've got a milltek midsection and i needed to make a spacer to get it the correct length.

I don't know if the downpipe section is the same length or not though unfortunately however a good exhaust fabricator shouldn't be troubled by different lengths.

If a different catted down pipe fits and ends up near the catback system it should fit enough for mot. Mine fit without the spacer it might just be too long or too short by an inch or two which could be sorter later by an exhaust place potentially if you just need it through the mot asap. Difficult to say without being able to see it.

 

Wouldn't worry too much about the "failure exhaust lambda reading after 2nd fast idle" if your car is running ok and you don't have any stuttering, hesitation etc. Your best (and cheapest bet) would be to take it back to your "friendly MOT place" again when VOSA is not around, as I doubt the car will pass emissions even with a cat on if it's been remapped by Bob. Mine didn't as he mapped it to run very rich indeed. They can stick the emissions probe in the car next to yours when checking your emissions if they're "motivated enough".

 

Yes it will pass, I have one and no problems for 3 years, just make sure it’s hot

 

Thanks for your help mate, it looks like my mate, has sourced a cat, which should be able to fit.

Does this mean that a new lambda sensor is not necessarily required then? Thanks for your advice mate.
Car runs sweet, with no sturttering or hesitations.


Thankyou for your help with this, much appreciated.

 

I guess having a catpipe fitted, I would require a new lambda sensor?

 

Can someone please confirm that exhaust lambda reading outside specific limits doesn't necessarily
mean the lambda sensor has failed, and that it could just be the decat pipe, and mods that could
cause this?

Thanks

 

0420 code ?
If so normal when you remove a cat.

 

Your stock lambda sensor is a narrowband and the remap was done with a wideband in place. The narrowband is bound to read outside limits after the remap if the car has been mapped to run rich, without it necessarily being faulty.
By the way, is your front lambda in the uppipe or downpipe?

 

I don't know what the code is? because mate took the car for MoT, and said failed with emissions, here is the MoT failure sheet:

Repair immediately (major defects):

1. Exhaust Lambda reading after 2nd fast idle outside specified limits (8.2.1.2 (c))
2. Exhaust carbon monoxide content after 2nd fast idle exceeds default limits (8.2.1.2 (b))
3. Battery insecure and likely to cause a short circuit (4.13 (a) (ii))
4. Nearside Front Outer Drive shaft joint constant velocity boot split or insecure, no longer prevents the ingress of dirt (6.1.7 (g) (ii))
5. Exhaust noise is clearly in excess of that emitted by a similar vehicle fitted with a standard silencer in average condition (8.1.1 (a))
6. Exhaust catalytic converter obviously modified (8.2.1.1 (a))

I don't know as the decat was fitted by previous owner before I bought the car?

 

The MOT tester did throw the book at you

a + b are pretty much the same thing. Your car is running rich so the tailpipe CO is high and calculated lambda value outside limits. Does not mean that your lambda is shot. It would be great to know what the actual CO values were, as a catalytic converters can only reduce them so much. So if the actual CO value is higher than a certain limit, there is no catalytic converter that will bring it down to a passing value without a remap to make it less rich. (which could prove quite expensive)

c just tie down the bloody battery

d same as c, just fix it

e he is getting really picky now the *******

f no comment

The front lambda should be either on the uppipe, driver’s side of the engine bay opposite the driver’s side chassis leg or on the downpipe just behind (after) the turbo, depending on whether it has been relocated or not. Either way, I doubt it needs changing.

I would fix c+d and then find a friendlier MOT place as if you were to address everything else that bugger reported, you would need to pretty much change your whole exhaust system from the turbo back + remap for it etc.

 

The book was thrown at me because VOSA were present at the MoT, so I have been unlucky. Interesting what you say about the Lambda sensor not being necessarily needing changing. I wasn't present at MoT, so just going on mates advice who took the car for MoT.

 

The lambda value at the emissions testing is back-calculated by the testing machine based on the emissions it is measuring. It is not a value that it reads from your front O2 lambda or your ECU, so if your car idles and runs alright then your lambda is fine
If you don’t know of a “friendly” MOT place already, I would ring Subaru specialists in your area (starting with the smaller ones) and tell them that your car failed due to emissions and ask them if they maybe provide a service where they swap their own used exhaust in temporarily etc so that you can pass your MOT. It will definitely cost you much less than buying a new catted turbo back system. Make sure you fix the battery and CV boot though first. Shouldn’t be that expensive.

 

Thanks for your help mate, much appreciated.

Will let you know the outcome

 

Took my x5 for test today too a tester I don’t know or ever even too as it’s decatted and my pal knows it’s decatted.

Wierdly because it has a massive plastic cover under most of the bottom of the car.... it passed

hes obvousley not allowed to remove the cover so was know way of knowing If it had cats on or not. Did comment that it sounded well... was thinking if only you knew lol.

 

These are a load rubbish, never seen that before.

Exhaust noise is clearly in excess of that emitted by a similar vehicle fitted with a standard silencer in average condition (8.1.1 (a))

Exhaust catalytic converter obviously modified (8.2.1.1 (a))

Just fit a Japspeed sports cat, 200 cell will pass easy, 100cell needs warming up. But even a 3" should match up, pipe might be abit thinner bolts should line up. My mate had a 2.25" back box fitted to a 2.5 standard centre pipe on his 1994 WRX, from previous owner.