P0420 Query

miniator

3rd time now ive had the engine light on, with the fault

P0420 - Catalyst System Efficiency Below Threshold. Bank 1.

Now, i know that its either or both of the lambdas (although they were both changed within that last 6 months) or its the CAT on its way out.

But, when the fault refers to bank 1, i assume it means a lambda...which one is bank 1 though!?

MikeS

you need to check if the front mixture lambda is working correctly - then i would move on to the 2nd lambda to see if it is working and finally the cat

so you need to read the sensor signals to interprete what this code means

has the car got a slight misfire when you accelerate at low revs ?

is it lumpy at idle especially when warming up ?

are you getting crap MPG

miniator

has the car got a slight misfire when you accelerate at low revs ? - no, i think the car is driving really well. granted i only have it a week!

is it lumpy at idle especially when warming up ? - it is slightly lumpy at idle when she is up to temperature. 100% when warming up

are you getting crap MPG - hard to say, again i only have it a week. I was say the MPG is good, 170miles to the first half tank so far on this tank!

how does one read the signal codes??

poundy

miniator said:
has the car got a slight misfire when you accelerate at low revs ? - no, i think the car is driving really well. granted i only have it a week!

is it lumpy at idle especially when warming up ? - it is slightly lumpy at idle when she is up to temperature. 100% when warming up

are you getting crap MPG - hard to say, again i only have it a week. I was say the MPG is good, 170miles to the first half tank so far on this tank!

how does one read the signal codes??

i get that code on mine at the moment, but i havent got a cat, but it doesnt rum rough or anything and the mpg isnt bad either.
i got one of those extension pices off e bay and im going to fit that when i have the exhaust done next weekend, so ill let you know if it works.

miniator

Cheers bud, didnt even know you could get them on eBay!

More investigation tonight has revealed that the cat itself is in good nick, in fact it looks like new!
The lambda probes also look fresh, so I just cleaned them with carb cleaner and tightened them up, where a bit slack!
Removed the pre-cat too (which makes an amazing difference to the car!!!)
Also, between the cat pipe and the middle box there was no clamp! One was duly fitted!

Disconnected the battery to clear the code....time will tell now!!

poundy

miniator said:
Cheers bud, didnt even know you could get them on eBay!

More investigation tonight has revealed that the cat itself is in good nick, in fact it looks like new!
The lambda probes also look fresh, so I just cleaned them with carb cleaner and tightened them up, where a bit slack!
Removed the pre-cat too (which makes an amazing difference to the car!!!)
Also, between the cat pipe and the middle box there was no clamp! One was duly fitted!

Disconnected the battery to clear the code....time will tell now!!

look here mate

http://cgi.ebay.co.uk/ws/eBayISAPI.dll? ... K:MEWNX:IT

miniator

Cheers bud!! Let us know how you get on!!