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Discussion Starter · #1 ·
Hi all,i have a car which recently failed its mot due to emissions problems. I now believe ive fixed it by fitting a new alloy throttle body in place of the naff plastic one. The idle seems back under control and it runs fine etc. Problem is,due i mot it again and risk failure/waste of money? It would be usefull if i could get the emissions checked before mot again,any ideas?, Is there a diy test kit? Im in manchester by the way...ta
 

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rover_45
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No DIY kits, but you could phone around a few suitably equipped garages and simply ask the cost of an emissions test only.

BTW; which readings exactly were over the limit? It may be your catalytic converter/lambda probe or a number of other causes. Knowing what the readings were may strongly indicate what's failed.
 

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I phoned Nationwide Autocentre the other day for a CAT quote and they said an emissions test is free!!! They just have problems fitting it in between MOTs.
 

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One further idea: my local council, in common with many others, operates its own fleet maintenance depot. They do their own MOT's and residents can pay to get their own vehicles tested there as well.
A sideline of this is that they will do free emissions tests on residents vehicles and I've learned that many other London Boroughs offer the same free service as an environmental protection measure.
I'd imagine that many other non-London councils offer a similar service. It's worth asking them!
 

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Discussion Starter · #5 ·
Hi There,well on the fail cert it says
1) Idle speed too high

2) emissions Lambda reading after 2nd fast idle is outside specified limits

3)emissions CO content after second fast idle -excessive


At the time the car (K16 engined) had the original plastic throttle body,it showed signs of being warped and letting air pass when it should have been shut. Plugging the diagnostics computer into the EMU at the garage at first indicated a faulty air throttle potetiometer but this was duff information. What was really suspected was that the air throttle wasnt shutting tightly. When the car was stopped/idling,air was sneaking past the air throttle even though it was shut. The EMU was being told it was shut by the throttle potetiometer but this conflicted with other sensors (air mass?) which could sense the excess air that was sneaking past. It therefore seems that the EMU was discounting the pot as being faulty,assuming becuase ot could see air flow,that the throttle was opening and so supplying extra fuel. Of course the mix would be all wrong!. The car was idling way too fast and whn driven,if throttled off at red lights,it revved up. Fitted replacement alloy air throttle body from late model scrappy and idle is back under control again. Hopefully it'll test ok..??

Obertelli said:
No DIY kits, but you could phone around a few suitably equipped garages and simply ask the cost of an emissions test only.

BTW; which readings exactly were over the limit? It may be your catalytic converter/lambda probe or a number of other causes. Knowing what the readings were may strongly indicate what's failed.
 

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Discussion Starter · #7 ·
fuel injection /emissions query

empsburna said:
can you post up the readings you got?
There we no readings given on the form VT30 (refusal to issue a test cert). I think the basic problem was that it just wasn't possible to carry out a meaningfull/valid emissions test as the engine revs just wouldnt settle down. One thing though,,how does the engine know how much air is flowing? All i can see is the throttle pot which would feedback info on throttle position,and an air temp sensor. How does the engine sense/measure how much air is passing into the air intake ?? The engine is a 1400cc twin cam dohc K16
 
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