I've had the 2.0 probe for five years and every single year there's been problems with emissions, HC and CO being too high, this year though only CO, everything else ok. During these years we've changed catalytic converters, lambdas, spark plugs and wires, MAF from 626, "new" 130k km 626 engine as the old one was eating oil really bad and ECU as the old one wanted to retire. No fault codes. Running too rich but why
. I wouldn't want to get rid of the car, but it's so annoying that year after year it's a nightmare to get the car inspected, no matter what you do to try fix it.
BTW am I right that there are three coolant temp sensors on the head, 1 for the ECU (green), 1 for gauge and 1 unused (black) that is used only in automatic cars or am I missing wires?