Am I going insane, p4020

[xkieron99x]

So I’ve docutment in my ownership build that for the last couple of months that I been battling a ineffienct cat issue, I’ve replaced the underfloor cat, o2 sensor, ensured there is no intake or exhaust leaks. I finally thought it must be the pre cat must be failed. My local Audi specialist (lion garage) are saying they have inspected the pre cat and can’t see anything wrong with it and it may be a fuelling issue. I’m unsure as there is no miss fire or rough running when driving even under full throttle and there is no other error codes reported in vcds.

What does everyone else think, could it really be a fuelling issue or am I right of thinking the pre cat has failed and garage is wrong

 

[samuelh_888]

You've probably already taken a look at this but if now then: http://wiki.ross-tech.com/wiki/index.php/16804/P0420/001056

As you're Leicester based, maybe book in for a diagnostic at R-Tech Garage (Nuneaton) or and alternative specialist?

 

[xkieron99x]

Yeah I did look at the Ross tech page and yes I am Leicester based so I’ll give r-tech garage a call. Let’s see what I get billed for at lion garage. Hopefully it just £50 for the diagnostics fee considering they had my car for week and half