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)