Lambda Sensors

[TOYOTARAV4RASHID]

My local garage diagnosed that my 2001 registered RAV 4(mileage-68k) has defective Lambda sensors and engine light is on. Driving is fine. Fuel consumption is fine as before. Do I need to replace this? Is this defect has any further consequences for future engine operation? How the defective sensors can be pin pointed and replaced? How much this cost? Will this defect affects the MoT test? Will my RAV 4 pass MoT?

Any suggestion /advise gratefully received and appreciated.

MR. Bristol England.

[gjnorthall]

You need to check for fault codes using a simple fault code reader in order to pinpoint the failure - there are 4 Lambdas on your car. The car will fail the MOT if the engine light is illuminated. Effects on the engine will depend on whether the faulty Lambda is pre or post catalyst and whether it's a heater failure or sensor failure.

[atkiman]

It will run ok.mine went 18 months with the engine lightvon, before it finally failed the mot on emissions.i had all 4 done and an mot , came to around a grand.but you can do it cheaper on a diy job.

[LeeroyJones87]

Hi TOYOTARAV4RASHID,

Technically the car won't fail it's mot if the light is on as that isn't a testable part. They may note it as an advisory item.

If you run the car with a faulty oxygen sensor (lamda sensor) it can eventually fail the mot because the emissions won't pass. Also if the sensor is before the catalytic converter, it can ruin the cat due to it running rich or lean.

Hope this helps

[Frank Wardrobe]

Take "ruin" as meaning "annihilate it and spray it out the exhaust as a fine powder"

- Steve Earwig (on his 2nd new cat and final kidney)

[LeeroyJones87]

No its not that bad. It'll just smell bad, but more the point that it won't go through the mot emissions test and will fail it's mot test because the cats internals won't remove the impurities.