Not Running right below 4k revs

[maxedracer]

Hey guys, ive been having this problem for a long time now and have spent loads on trying to fix it. Basically below 4k revs it feels like the car has a mind of its own, I'll be driving along and my foot will be steady on the power but the car will go faster then slower on its own, like im feathering the throttle. Its almost like there is a blockage somewhere. Sometimes the exhaust also splutters a bit as well. If i remember right , it all started about a year and a half ago when i had the yozza sport de-cat race system fitted to it. Strangely though even though its a de-cat the emissions light has never come on which leads me to believe one of the lamda sensors isnt working ?

I recently came upon this on the forum

Poor running up to 4k. This can be put down to a failed lambda sensor in the exhaust, below 4k the engine runs an open loop the readings from this sensor being used to adjust the fueling above 4k these sensor reads are ignored as to inaccurate. Replacing the lambda sensor is an easy fix option.

Has anyone had any experience with this problem ?

 

[regi james]

yeap this happened to me renault replaced O2 sensor under warranty, but you could swop the two over im sure they are the same

 

[realnumber 1]

Yep, I had the same problem. New sensor and all was well again.