7 replies to this topic

[redvts]

my scangauge came today, its really good, anyway i bought it because my check engine light was on, the code as you can see in the title is P0420, searched through old posts but couldn't find a definite answer as to what this means, can anyone help????

[chris_uk]

P0420 Catalyst System Efficiency Below Threshold (Bank 1)

full list

http://www.z22se.co.....php?f=3&t=3980

Edited by chris_uk, 28 July 2009 - 04:31 PM.

[Pooh Bear]

In the instructions to the Scangauge it simply says to "google the trouble code" with the make of vehicle ie Vauxhall followed by P040. Give it a try as few results are thrown up... edit: with the answer Chris uk has given

Edited by Penny, 28 July 2009 - 04:30 PM.

[redvts]

tried that but doesnt point to anything specifically, cat knackered, one of the two lambda sensors is goosed or the egr valve is no good

[chris_uk]

P1404 is the EGR fault, thats what i got anyway, im not saying it wont be that but id look at the 2 lambda sensors first. if you local to anyone ask to swap them and see if they get the fault using your lambda, and see if your fault clear using theirs.

[redvts]

how hard are the lambda sensors to get at, do u need both rear underplates off?

[aron916]

I get this code every now and again since getting my 200cell cat! On the scangauge, just scan for the code and then clear it...light goes out!

[redvts]

yeah i cleared the fault last night but mine is a standard cat so there must be something up, on saying that ive driven about 40 miles since and it hasnt came back on