Last friday i took the coupé for the MoT and all was going well until the emissions test. Looked good to start with then the CO started rising on idle and going stupidly high (5%++) when the revs were brought up.
Checking a few obvious (aka silly) things revealed nothing and the only clue was the yellow LED on the PGM-Fi ECU was on steady (idle too low) so i paid up and went home. Two miles from home, the PGM-Fi light came up on the dash. Looking under the seat at the first chance revealed a single solitary flash of the red LED every few seconds, pointing to the front Lambda sensor being dead.
On past experience i ordered a pair, knowing if one dies the other won't be far behind.
The new Lambda sensors landed today about 1030 and the rear one took about 10 minutes to fit, including cutting and crimping the old lead (with the connector) onto the rather short lead from the sensor.
The front one took 7 times as long! Firstly it was harder to get my paw into the space available and secondly, every time i got a few turns on the thread, the sensor unwound itself, as if on a clock spring! Seriously! I didn't believe it either but i watched it happen! Eventually i got enough turns of the threads in to hold it in while i fitted the Lambda socket and tightened it up properly.
I got the carb cleaner out and (once i'd refitted the ECU memory fuse), fired it up and gave a good few squirts in to clean out the EICV and throttle body in general.
Then i took it for retest :
"Can't get much better than that!" - the testers words not mine!
Combination of good maintenance (i know, i know, i should have spotted the dying Lambda but it genuinely died in action on the emissions tester first time round), a pair of new Lambda sensors and giving the cat a good soaking in several dishwasher tablets and a load of hot water! The amount of sh!te that came out of the cat, it's no wonder it struggled in previous years to meet the emissions!
But there we have it, another years life for my coupé!