emissions / stuck at mot

[Schakal]

its a 1998 clio 1.2 d7f engine , failed mot on emissions .


EXHAUST EMISSIONS LAMBDA READING AFTER 2ND FAST IDLE
OUTSIDE SPECIFIED LIMITS

the problem seems to be with the lambda readings at fast and 2nd fast idle tests.
here are the readings ;

FAST IDLE : MIN-MAX LIMITS = 0.970 - 1.030 ACTUAL = 1.065

2ND FAST IDLE : MIN-MAX LIMITS = 0.970-1.030 ACTUAL = 1.058

any ideas as to what might be causing this ? cat ,lambda sensor or
may be a leak around the cat joints ?? :confused:

[paul b]

high lambda readings are usually a leak on the system......
or fault on Lambda sensor ......

High CO readings is usually cat related but NOT always...


check for any leaky joints or even a slight manifold blow.....if not see how much a new lamda sensor is, its sometimes cheaper to replace than get it plugged into a diag machine

[mad manz]

if u want a mot it can be sorted even with **** emission :smokin:

[Schakal]

high lambda readings are usually a leak on the system......
or fault on Lambda sensor ......

High CO readings is usually cat related but NOT always...


check for any leaky joints or even a slight manifold blow.....if not see how much a new lamda sensor is, its sometimes cheaper to replace than get it plugged into a diag machine


thanks paul did not want to take all apart before knowing what might be wrong .
i guess there might be a leak ,but its hard to see .
is there a way to check if the sensor is faulty using a multimeter ?

[Chris Hebden]

Was the CAT exceptionally warm when it was on the tester?! What we used to do was take the car out, get the CAT really warm and it would make a big difference!

[Schakal]

Was the CAT exceptionally warm when it was on the tester?! What we used to do was take the car out, get the CAT really warm and it would make a big difference!


no it was not warm at all ,thats one other thing i will do
before taking it for a retest . abuse it with added redex :burnrubber:

[Chris Hebden]

Blast it (legally of course) to the MOT station get it on the analyser straight away and bobs your aunty it should be groovy!

[Schakal]

found out it was blowing out on the rear joint(back box to mid section) which i have sealed up a few days a go :cry:
had to bang the pipe further in with a hammer and re-tighten the clamp
hopefully this was the cause cause i cant see anything else out there .

[Schakal]

gave it a good blast on the m4 before taking it to the
retest and passed nicely :p
thanks for all the support people :)

[Chris Hebden]

No worries mate, glad you sorted it! :D