Hi, I had a whole new exhaust fitted yesterday with Kwik Fit (including cat). I started the car this morning and for the first 10-20 seconds the exhaust is making a rumbling noise on start up and for the first few revs. Best way I can describe the noise is like a boy racer exhaust. I work as a community carer so the car is stop start all morning and it was making this noise for the first few hours until eventually going away. However having been idle for a few house this afternoon I went to start it up and it made the noise again. Is this normal? Any help would be appreciated. I did take it back to kwik fit after work and they could find nothing wrong, although they didn't hear the noise I'm describing as by that time it had stopped. Thanks.

Bottom line is that nothing will be remedied until KwikFit actually hear, and agree that the noise is indicating something wrong. I'm afraid you'll need to take it back to them when you can judge the noise to be worst, on start up... Pointless us trying to guess what it is, as even if you do get opinions, at the end of the day the only way to fix it is down to KwikFit...

It is normal for the exhaust to sound "tinnie" for the first few hundred miles or so. A used exhaust is full or carbon sutt that dampens the sound a little where as a brand new one has all those sound waves bouncing off clean metal.

At the same time it depends what exhaust they've fitted as to what noise you'll get. If for some reason the back box isn't the same size or the cat is more of a sports cat then it'll always sound like a boy racer car.