car failed mot on high emissions , skoda felicia 13mpi , just scanned it and its giving 3 faults 00525 o2 sensor voltage low /. then 17978 contol module locked ? then 01247 ev ap canister purge regulator valver -n80 ? so me thinks new lambada sensor . but the other 2 faults i dont know what they are i think one is the charcoal canister if so is it a new one or can it be cleaned out i have now cleared the faults with the scanner . so do you think i may just get away fitting new o2 probe ? thank you sean

Edited 11 November, 200916 yr by spock

I've had the canister fault on mine, made no difference to the emissions per se - it's more about evaporative emissions, stopping the fuel evaporating into the air, I believe.

ok great so you are saying that i dont need to change the valve for emissions. ordered a universal sensor of flee bay £18 and hoping to take it back this week thanks sean

A blocked emissions canister can cause excessive fuel consumption; the purge valve releases gas build-up in the canister after you switch the engine off, so doesn't cause the problem itself, but if the can is not returning fuel to the tank correctly THAT can cause the mpg to drop badly; so keep an eye on it.

hang on i think you've mis-interpreted the function of the charcoal canister. it makes no difference on the fuel consumption whatsover wether it's there or not, all it does it collect vapour from the fuel tank via a long rubber hose then stores the vapour.. the purge valve then introduces the vapour into the engine under cruise/light vacuum operating conditions. NO fuel goes back from the can into the tank... this whole system is just to reduce harmful emmisions from the from the fuel tank and plays no part in the ecomony of the engine....

as an aside note to this, on some of the rally cars which have no cfsv or canister you need to use a different type of fuel cap with vent holes in it to prevent tank vacuum from restricting fuel delivery

in regards to the op, i should imagine your evap code will magically vanish when you've replaced the o2 lambda probe, having a fault on that prevents the ecu going into closed loop operation and hence disables the evap system.... 17978 refers to the immobilizer system, but i guess as this car is a runner then there's naught to worry about with it, may have just been stored in there a long time

Edited 13 November, 200916 yr by TeflonTom

On my Toyota the can is part of the fuel return system, and I assumed it was the same with all cars; it feeds fuel back into the fuel tank when the engine is running, and vents any vapour build-up when the engine is off.

When the can got blocked my motorway fuel consumption was the same at 80mph as it was at 50 (18 MPG!!); getting a new one fitted returned my average 70 MPH fuel consumption to 25 MPG on UK fuel and 30 MPG on French fuel.

Toyotas can be a bit weird though.

thanks for reply s failed again this morning replaced c02 sensor . no codes now present so i and lad at garage think its the cat , i said what about rings but he said the smoke would be more and the hc reading will be higher so cat it is .

as a side note. fuel mpg on this car is fantastic best i have had so far .

fast idle test .co 0.63% fail passed all other on fast idle . second idle test co 0.64% fail passed all others . natural idle test co 0.55% fail now do i change cat . or reading another post but on a 1.6 he changed coil pack bingo . this car has had new plugs oil and filter change new co2 sensor and is showing no codes now ? ideas please before i lash out for a cat

bought new cat put it on half hour ago , passed mot

Edited 18 November, 200916 yr by spock

passed

Edited 18 November, 200916 yr by spock

passed thanks to all who replied

Just a note to anyone who has an apparent Felicia emmission problem. Car Mechanics Mag for this month has an article (on Page 12) about thermostat problems being wrongly interpreted as Cat failure. Well worth getting a copy _ _

also i have a code reader anybody needs to find faults bolton lancs , going to buy me a vag com lead for the laptop also got obd11 software on laptop thanks sean