Engine Code P0130 + Limp Mode

[GuestGuest9]

Just over the past week, my Renault Clio MK3 RS200 first struggled to get over 3.5k rpm when cold, and now it just won't go above 3.5k at all, even when fully warmed up. I can't go above 55mph in 5th gear without the engine sputtering and struggling. I've used an OBD and got the error code PO130, which links to the pre-cat oxygen sensor. The thing is I can easily rev the car past 5k when the engine is stationary. But the moment I'm moving, I'll hit a wall at 3.5krpm.

Could these two be related?

If so what do I need to replace it and can it be done at home? A garage quoted me £240 for the sensor alone which seems way too much.

 

[GuestGuest9]

Apologies, I meant "can't go above 55mph in 6th gear"

 

[Brigsy]

PO code means nowt, need df codes really .

At a wild guess lambda is reporting lean mixture and fuel pump is on its last legs, but very hard to say without proper diag