engine fault code help

[hipwell]

Well my emmissions light has come back on so theres definatly something wrong as it failed the emmissions test on the mot last week.

Car is running perfectly fine, averaged 41mpg down the motorway earlier.

Ive got one of those cheapo hand held code readers you can get from ktec and all its saying is fault 1 , n/a 01/01.

Any ideas before i pay some garage 30 quid to put it on the diagnostics?

I was under the impression that if it was a lambda fault then the car would run poorly.

 

[Missing Link]

The lambda may be lazy or stuck, A live readout would show you it swinging ( rich- Lean)

Just back in from a Saab running the same symptoms

http://www.obd-codes.com/p0420

 

[hipwell]

Would it be worth swapping the front and rear lambda sensors over be worth a try then as as far as I'm aware the after Cat one does nothing anyway.

 

[Missing Link]

Not really, The second one is there to make sure the first one is working.

On my Phase 1 there is only one lambda probe, It ran like sh*t when i floored it but never showed a fault on the dash.

Only when i plugged it in did it show up as lazy ( no real swing ) If it had a second it would have flagged it up.


Check the obvious first, no air leaks at the downpipe. Even the slightest leak/crack can upset it.

 

[hipwell]

The link you posted says a dodgy coolant temp sensor could be an issue.

I've noticed that my cooling fam doesn't come on even if I leave the engine running for ages, however the fan does work because it comes on with air con.

Does this suggest a dodgy sensor?

 

[Missing Link]

Best bet is to get a plug in fella, Only then can you really suss it out.

Lambda's are £50 a pop and a sensor could be £20 odd, You could spend a few quid buying bits.

Fan will come on with A/C to control A/c Gas temp.

Thermostat could be stuck open not allowing the the emissions system going closed loop.

But again this is all guessing !!!

 

[hipwell]

Ah right. Yeh I know, but what I meant is that the fan must work to come on with the air con, so it could be a possibility that the coolant temp sensor isn't sending the correcct info to the ecu.

Looks like best thing will be to get it plugged in then, wish I had an rstuner now.

 

[Missing Link]

Had a dig about. If your machine is meaning to give a fault code of P0101, This relates to poor performance on the MAF ( Mass Air Flow meter )

http://www.obd-codes.com/p0101

 

[Lagerlout]

I got the same 01/01 N/A fault shown on the hand held reader I have. Plugged an RSTuner in and it shows up as 'front 02 sensor heater fault'.

My front lambda does swing pretty well mind, so I'm not really too sure what to do. Might just bite the bullet and swap the lambda.

http://i3.photobucket.com/albums/y72/lagerlout1/untitled.jpg

 

[MrBlonde]

I know this thread is old but I have had the same code pop up on my reader and car is driving fine,did you get a solution??