Emissions

[arthill]

Hi

I had omissions checked recently  and lambda part of readings was too high and maf was suggested to as possible cause, changed it and had readings done again and was fine, but as TB said it may be something else that is flagging that up. in my case maf was flagging lambda fault.

John

[Kevin Wood]

yea was thinking it might be, will see if it comes up again lol good call by kev if it is, and for the sake of a few quid (im guessing, as they usually are) ill replace it

It's reporting the lambda as open circuit which does tend to suggest it has failed. However, with emissions that far out I might be inclined to think that the CTS is bad too. :-/ Wth the cat not working, I'd only expect about 2% CO if everything else is in order. Lambda could have failed as a consequence of a bad mixture (like, I suspect, the cat did).

It's a cheaper fix than the lambda sensor so I'd be inclined to give it a try. Failing that, if you've got a multimeter handy measure the resistance of the CTS both with the engine cold and hot. Easiest to look on a wiring diagram, work out the pin numbers at the ECU and test it there because it's awkward to get to the sensor. At a guess you should see a few hundred ohms when hot and over 1000 when cold but at any rate there should be a substantial difference.

Alternatively, get the live values checked on a tech 2.

Kevin

[barclay03]

ok, went out for a wee check under the bonnet to see what im going to attack, and noticed that the AMF didnt have its plug inserted, it was cabletied up with the air temp plug... so pluged it back in and its definetly runnin like crap... so im assuming thats nackered and need a new one? (mate has new one anyway) and go from there?

done paperclip test again and understood it a bit better, codes showing are:

73   Mass Air Flow Sensor Voltage Low
74   Mass Air Flow Sensor Voltage High
135   Telltale (Checklight) Voltage Low

[TheBoy]

ok, went out for a wee check under the bonnet to see what im going to attack, and noticed that the AMF didnt have its plug inserted, it was cabletied up with the air temp plug... so pluged it back in and its definetly runnin like crap... so im assuming thats nackered and need a new one? (mate has new one anyway) and go from there?

done paperclip test again and understood it a bit better, codes showing are:

73   Mass Air Flow Sensor Voltage Low
74   Mass Air Flow Sensor Voltage High
135   Telltale (Checklight) Voltage Low

The MAF ones should go after a while once MAF fixed.  The checklight was due to no bulb at some point (to cover MAF fault?). Don't think this code clears itself, can't remember.