failed nct last week high reading lambda , 50k miles on engine and the garage wants to replace the cat ? i would be of the opinion that the sensors would be the culprit anyone have any experience of this problem thanks

failed nct last week high reading lambda , 50k miles on engine and the garage wants to replace the cat ? i would be of the opinion that the sensors would be the culprit anyone have any experience of this problem thanks

There is a fuel-additive system cleaner commonly used in the trade, under the brand name "FORTE". It is available in formulations for Diesels, petrol, and older Fiesta petrol engines which had sticky valves, + they also do a sump-flush additive. It is very well respected in the trade, but is not generally found in car accessory shops, as it is labelled "trade only". It can be found in garage store-counters at £8.50p + VaT, and the internet, and Ebay. I have used it for 10 years on diesel and petrol cars, and have seen other accolades on car owner forums, including from mechanics.

It is capable of cleaning all surfaces from the fuel tank to the tail-pipe, and is most effective when added to a low level of fuel in your tank, and burn it away before a retest.

In any case, I wouldn't replace the Cat, just do the Lambda probe first, and do it yourself to save cash.

With "FORTE" in the fuel, a fast hot run down the motorway, should clean-off the Cat, and Lambda, and injectors/plugs, but a change of plugs and air-filter first may be a good plan, also a mini-service of oil/filter, as old dirty oil gives off noxious fumes, that get put thro' the crankcase breather pipes to be burnt in the engine, and can crud-up the filter and air-inlet throats/injectors/etc.

SO, a bit of TLC can save a lot of dosh, unless there is a hole in the Cat core.

there is a sensor in engine bay just at the exhaust header and one under the car where the cat ends , i take it the one on top is just a sensor the bottom one is the lambda probe ??? i already gave her a service (plugs oil and both filters )so i'll give her a lambda sensor and a bottle of forte , cheers donframac

there is a sensor in engine bay just at the exhaust header and one under the car where the cat ends , i take it the one on top is just a sensor the bottom one is the lambda probe ??? i already gave her a service (plugs oil and both filters )so i'll give her a lambda sensor and a bottle of forte , cheers donframac

Some vehicles have 2 lambda probes, others just the one that is prior to the catalyst. The one nearest to the engine is the one that gets dirtied most by inaccurate fuelling, but if your car has 2, I would let the "FORTE" do its job, and see if that is enough, lest you need to renew 2 probes, as they are not cheap. (My Son got one fitted above the Cat on a SEAT IBIZA 1.2, after it got knackered by a failed coil-pack, and that was done at cost,--£85, would have been £200 inc labour & VaT) All his 3 coil-packs were renewed before the lambda probe renewal. P.S., probes can be very difficult to unscrew, due to rust, and a blow-torch is often needed.

A bottom probe would suggest you have an exhaust gas recirculation system, with an EGR valve, which can need cleaning, but this additive will help this unit work better, but it can be manually decoked also.