Error Codes P0420 & P0420P

[Geon]

Hi

I've got the above codes showing on a diagnostic test and it all points to a cat problem.

I've taken it to an exhaust centre and they have said that there is a slight blow by the cat and have been told it will need replacing. Lexus can't be bothered to call me back so I'm hoping ths forum will help me.

Any quick fixes or is it main dealer and a bucket load of cash!!!

Thanks for your help in advance

[steve2006]

Hello and welcome to the LOC.

The fault codes indicate an inefficiency with the Cat but further diagnostics should be performed before condemning it as it could be a sensor problem or a fueling problem.

If there is a slight blow by the cat this should be sorted first as the O2 sensors can be misled by this and flag up a fault code(s).

A member recently had the Y pipe sucessfully repaired saving around £300 on a replacement.

By the way is the engine management light on?

[Geon]

Yes the light came on yesterday. The garage only found a minor blow by the exhaust / cat, what do you recommend as a quick fix before venturing further.

Thanks for the reply

Geon

[steve2006]

See if the leak/crack can be welded up and go from there.