Hi lads, done a search and cant find what im looking for. Basically cars idle is at 3k and its missing pretty badly on and off. Revs problem started when the chip was added but was misfiring before. 1 day ive had it bk and its already playing up!

I see that you all try replacing different sensors etc etc to try sorting it. Why doesnt anyone just go to renault and let them plug it up and tell you whats wrong? Cant they do it accuratly or is there another reason? Just wanting mine fixed now