hi all. ive been getting a cel with the code p0420 on and off for about a month. been to the dealers twice, they put new plugs in and checked the lamdas were giving the correct voltage, they said they were ok. my car is a 01 with 44000 miles on with a k and n replacement filter as the only mod. do you think that i could get the cat replaced for free because surely this should not happen on a car with this kind of milage? anybody else had this trouble, thanks for any help.

 

Cats are expensive to replace unless you can get one from a breaker.

You could always remove the cat and replace it with a de-cat pipe.

 

Well if both lambda's are ok by their judgement then it probably is buggered. I suppose you could get an emissions check to verify it.

If it is the cat I would be angling for a new one - might be in vein but with those miles it pretty poor.

Maybe someone on here with a decat can loan you their cat to see if it works?

A breaker would be a good bet if you have to pay for it, as Steven says. Its rare they fail.

PM me if you need to purchase your own ECU code reader / reset tool.

 

The only way cats die is from external damage (impact) or emmision fault. Most common to be front lambda at fault (rear has no bearing on the ems, it merely tells you the threshold of the catalyst)

If you replace the cat which is the problem you may leave the cause in the system so the cat wont last long at all.

Join my GB on high flow cats, save you a fortune but you really must get a decent garage to ensure your lambda is switching correctly.

L6

 

https://www.s2ki.com/forums/index.php?showtopic=454577

 

thanks for your views but i cant understand why its so intermittant it could be two weeks or two days for the cel to come back on. car runs exactly the same no loss in power. and mot emmissions fine. any advice. thanks

 

Lloyd thats not quite true, they can break up and also have to cope with extreme heat, so any slight manufacturing fault will become a quick weakness.

The chap has said the front lambda has been tested and ok.

The rear one is there to help tell you if the first one is buggered, or if your emissions are genuinely high.

Nice sell job though (decat is a good mod though )

If no power is lost and emissions are fine then it must be something else.

Is your idle ok and using same amount of fuel as normal?

Let me ponder...

 

yes idles fine and no change to fuel consumption i also checked lambda wires and plugs, they seem ok.

 

did you manage to come up with any suggestions? thanks

 

What fuel do you use?