Fiesta 1.4L MK6 high CO

Mates Fiesta Flame 1.4L FXJ engine has failed MOT.
High idle 1
CO 0.38 (0.2 limit)
HC 74 ppm (200 limit)
Lambda 0.996 (0.97 - 1.03)
FAIL
Hige idle 2
CO 0.15
HC 51
Lambda 1.004
Pass
Nat Idle
CO 1.11 (0.3 limit)
FAIL
Was told he needed a new cat £300 and they might damage the 02 sensors
+£100.
Front O2 sensor reads near 0.9V at idle and cycles 0.1V 0.9V at high idle.
Rear O2 sensor 0.4v cold. Rises slowly when held at very fast idle 4000rpm
to >0.8v. Drops rapidly to about 0.1v when throttle snapped shut and then c
limbs slowly back to >0.08V. Is this slow response and initial bias correct
?
The car is rarely used outside 30/40 limits and owner drives nicely. Last M
-way trip was Xmas. The "Italian tune-up" is no longer an option as the MOT
expired last week.
Car had a misfire problem about 2 years ago, had to replace plugs and coil.
(using google groups as not at home)
Reply to
Peter Hill
first Q. was it fully hot when tested? if so, does the ecu know the correct engine coolant temperature?
Reply to
MrCheerful
rpm to >0.8v. Drops rapidly to about 0.1v when throttle snapped shut and th en climbs slowly back to >0.08V. Is this slow response and initial bias cor rect?
st M-way trip was Xmas. The "Italian tune-up" is no longer an option as the MOT expired last week.
I have no idea about test condition as (they always do) they by-passed all checks "engine temp showed warm" but it does that when still quite cool.
I got coolant up over 80deg C (forscan and torque) to get response from rea r sensor.
No lambda/cat related codes stored.
Reply to
Peter Hill
I would get a second test done and be sure it is actually hot. Also check there are no exhaust blows anywhere as that can throw things out.
Reply to
MrCheerful

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