Hi guys I'm getting code po420

[matt136]

Is this the first 02 or the second as it just has bank one, but from what I can tell is there both bank one just 1 & 2.

Was going to change these first as cheap cheers matt

[matt136]

Sorry, your post isn't making any sense at all??????

Hi I'm sorry will explain better, Im getting code po420 which is 02 bank 1 out of working range, was just wondering if this is the pre cat 02 or post, as it only said bank one not S1 or s2'

Dose this make sense?

[jong123]

Sounds like an imbalance between the Lambada sensors meaning it is out of percentage range.

Catalyst could be on the way out.

However I had a 2 liter MK1 estate that would throw up this code randomly and still passed the emissions for the MOT for 5 years in a row even having changed the Lambada sensors.

I cancelled the code with a cheap reader and put Redex in at every fill and avoided cheap fuel by using Shell.

I have a MK 2 hatch that is doing the same so will carry on until it fails the MOT then change the catalyst. 

[matt136]

Hi Jong thanks for the reply I only use shell v power I did test the cat with temp gun and its seems to still be working ok as about 100 deg hotter on the outlet side, then the inlet although I did remove the pre cat the other day and that was abit melted! The car has 90'000 so maybe time for a new cat,

Next question how much are they

Edited 27 April, 2015 by matt136

[jong123]

I use GSF, good quality items as original supply.

Check their web site they occasionally have 35% off at weekends.