How to tell if lambda sensor needs changing?
Long story short, I have noticed a couple of times now that the unbuilt computer milage per gallon reading fluctuates. It has happened twice now and I'm wondering if this is either a lambda sensor failing for a short period of time giving bad fuel economy, or the computer reading was temporarily playing up, or there is a problem with the accelerator giving false readings making the computer think the pedal is being activated harder than it is.
Eg: when coasting in neutral at high speed the car usually shows 50km/l, and when on cruise control at 120km/hr it generally shows between 17-22km/l depending on how level the road is. How ever two times now I have noticed the actual read out saying 22km/l when coasting in neutral and 8-12km/l.
Anyone had something similar???
Might be worth noting that every now and then it is as I the accelerator sometimes gets into a mini limp mode, this happened once for about 20 minutes ages ago and no one could work out why, there was no fault code, and today this happened for literally 5 seconds and revs wouldn't go past 3000rpm until I held the accelerator to the floor for a while.
Any comments on either issue?