Rover 200 & 400 Owners Club

K540WRP failed MoT on emissions, on CO : fast idle 0.48% (max 0.30%), second fast idle 0.52% (max 0.30%), natural idle 1.81% (max 0.75%).

Lambda fine (1.02 on fast idle, 1.00 on second fast idle),

Hydrocarbons fine (117 ppm, max 200 on fast idle; 74ppm max 200 on second fast idle).

I suspect the cat is shot and this was what the tester was leaning towards. What do we think ?

Nook it back in Take it for a blast down to motorway and drive it like it's stolen before it retested , if that fail disconnect camcover breather pipe from the cam cover and bock up . First one works for me the engine as to be red hot and second one worked year ago on a 216 that had piston ring trouble.

It could also be a problem with the coolant temperature sensor as this can cause K-series with mems to run rich

Should add, the car has had the following new items fitted in the last 6 months or so:

• coolant temperature sensor
  air intake temperature sensor
  spark plugs
  HT leads
  rotor arm
  dizzy cap
  oil filter and oil change
  air filter
  fuel filter
  line from fuel trap to ECU cleaned out
  all breathers/lines checked and replaced where needed
  front exhaust section (incl flexi)

New cat put on by my good self, just waiting on a re-test probably early next week now

Cat additive and an Italian tune will get that figure down.

Cabby failed emissions, quick' Italian Tune' to 'warm up the Cat' and it passed ok.
Had a Fiesta that had the same issue, failing emissions several years. Then they started doing emissions test as soon as I took it in after a hard run and it passed. Sitting at idle while they poked about underneath just let the Cat lose its efficiency.

Agreed, if I get up early enough tomorrow, I'm gonna lob a few litres of Shell petrol and some Cataclean in there for good measure, and then give it a razz down the M1 in 3rd/4th for a junction or two, before rocking up at the test centre.

Gotta pass this morning, well happy.

So, new cat, bottle of Cataclean, Italian tune up, testing station ready and waiting with the exhaust probe.

Emissions this time ?

Fast idle CO NIL
Natural idle CO NIL

Bingo bango

Nil

Was the probe plugged in?

Best I’ve ever had was 0.2 of the 0.3 max