So I recently purchased a 2011 Jaguar XF 3.0 V6, got it checked out by a mechanic and everything passed with flying colours (just over 60k KMS on the clock).

However recently on a long drive back while testing the acceleration I got a solid check engine light so plugged in my ODB2 reader and got the P0420 error back: Kinda a bummer but considering something a bit more major could have gone wrong I feel like I got off easy (although I might also be deluded as I am a layman)! I performed a test of the oxygen sensors and it doesn't seem to be a failure on their part sadly. I also checked for any misfires for each cylinder to make sure the CC wasn't blocked and there were none.

I'm going to get a mechanic I know to take a look but I have also heard about some petrol system cleaning products that can also help lubricate the engine and clean the catalytic converter a bit.. So my question is is it safe to put something like a fuel systems cleaner in the car? For me I'm sort of taking the attitude of it couldn't hurt considering the age of the car it could probably do with one?

Many Thanks

 

I had the same errror , fed a can of this

Penrite Pro Series EGR & Catalytic Converter Cleaner 500ml - PSECC0005

through the brake vacuum boost line hose directly into engine, cleared the code and seems to work very well since.
Risks ? dunno :shrug:

 

Great thanks! I'll give that one a go!