MOT Failure
#1
Scooby Regular
Thread Starter
MOT Failure
Hi guys just looking for some advice with regards my MOT failure. My car failed on exhaust lamba reading high and exhaust carbon monoxide content high after 2nd fast idle.
Does anyone know what I should be replacing to get these readings low enough to pass the MOT
Any help appreciated.
Does anyone know what I should be replacing to get these readings low enough to pass the MOT
Any help appreciated.
#4
Scooby Regular
Thread Starter
Thanks for the help much appreciated. Its got 2 cats on exhaust currently it has recently had a new back box put on with a bigger exit on.
But it passed last year with the same exhaust system with cats and smaller exit. so Im guessing the cats are on there way out maybe. Would it need a another MAP due to bigger backbox on the car?.
But it passed last year with the same exhaust system with cats and smaller exit. so Im guessing the cats are on there way out maybe. Would it need a another MAP due to bigger backbox on the car?.
#5
Scooby Regular
iTrader: (5)
If you have lambda values outside of the limits, it's probably nothing to do with cats etc. Even with a decat my lambda values were in the right range, but CO was way out.
If you have an OBD2 interface, you can read the lambda values as reported with e.g. Torques on a phone (assuming the obd2 interface has bluetooth). If the reported lambda readings are OK, but the MOT says no, then it's probably a lambda (oxygen) sensor issue.
If you have an OBD2 interface, you can read the lambda values as reported with e.g. Torques on a phone (assuming the obd2 interface has bluetooth). If the reported lambda readings are OK, but the MOT says no, then it's probably a lambda (oxygen) sensor issue.
#6
Scooby Regular
iTrader: (3)
If you can gain access to live data as suggested, check the lambda readings, with the engine off but ign on, they start to be above 1.0 when failing or heading higher,
Where a new sensor reads around the 0.80 mark,
100 cell is going to be a pain to get hot, as it flows so well, I struggle with a 200 cell, but a really good "Italian" tune up before sorts that.
Where a new sensor reads around the 0.80 mark,
100 cell is going to be a pain to get hot, as it flows so well, I struggle with a 200 cell, but a really good "Italian" tune up before sorts that.
#7
Scooby Senior
iTrader: (1)
Yeah, I would guess its a sensor issue rather than CAT failure if you still have both CATs in place. Replacing the back box doesn't mean you need a map either. It could be that you need some Cataclean through the system and give the car a good run keeping it in high revs to get the CATs smoking hot to burn off deposits. Either way, it is often the simple things that will make it fail emissions rather than the CAT itself.
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#8
Scooby Regular
Thread Starter
Im hoping its something simple lol its booked into Subaru but they cant see me until next week . But in the mean time I can try the cata clean route to see if that helps with the readings
Are obd readers able to read things like that or are they just for lights on a dashboard? Thanks
Are obd readers able to read things like that or are they just for lights on a dashboard? Thanks
#9
Im hoping its something simple lol its booked into Subaru but they cant see me until next week . But in the mean time I can try the cata clean route to see if that helps with the readings
Are obd readers able to read things like that or are they just for lights on a dashboard? Thanks
Are obd readers able to read things like that or are they just for lights on a dashboard? Thanks
Obd and the likes of btssm can display all values from the ecu such as fkc and timing etc.. Really good actually
#10
Scooby Senior
iTrader: (1)
As said above though, the OBD readers are great and display real time info, very handy.
#11
Scooby Regular
Thread Starter
What I have found out after contacting many garages is that a lot of so called specialist garages want nothing to do with Subarus. I thought it would be a dream to be let loose on a car like a Scooby but perhaps Im being biased lol
#12
Then your contacting the wrong garages haha. Where are you? Sure someone can recommend a garage in your area or not far from
#13
Scooby Regular
Thread Starter
Im based in Wiltshire the nearest specialist that I can see is Subarus 4u which is in Newbury but thats to far for me to drop my car off for someone just to look at it especially now the MOT has run out, maybe theres someone closer
#14
Scooby Regular
A good Subaru specialist will save you no end of hassle in the long run, so it's worth driving a little further in my opinion. As long as you have an MOT booked and the car is safe I think it's legal.
#15
Scooby Regular
iTrader: (1)
http://tetburymotorcentre.co.uk/
They used to be a franchised Subaru dealer back in the day. Unassuming old-school garage. MoT all my cars there and give them my Impreza's when the job is too difficult or I can't be arsed
If you book an MoT with them then no issue driving there on the day.
They used to be a franchised Subaru dealer back in the day. Unassuming old-school garage. MoT all my cars there and give them my Impreza's when the job is too difficult or I can't be arsed
If you book an MoT with them then no issue driving there on the day.
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Steve Whitehorn
ScoobyNet General
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27 April 2007 11:31 PM