Hi all,

My Zafira 1.8 Auto has an hesitation when at idle revs. Once on the move it is absolutely fine and accelerates fine. It is most noticeable when at junctions whilst in 'drive' waiting to move again, where the car can be quite juddery. It does not really register on the rev counter though.

I had to replace the rear silencer when I got the car as it was blowing a little and was vey rusty and worn compared to the other sections. I thought that this might be the cause of the hesitation but it is still there. I believe that the exhaust also has a small leak from the seal after the Cat. I also know that the thermostat needs replace as it is stuck open but I don't think that that would be be the cause of the hesitation. I have changed the air filter.

I can't say whether or not this is affecting the fuel economy as I am not sure what I should be getting, I filled the tank recently and have used just over a quarter of a tank covering 185 mile (combined motorway and town driving). Not sure if this is good or bad.

I am considering removing the throttle body and cleaning it. According to an invoice with the car it has had the MAF changed 15k ago. I had an MOT done a couple of weeks ago and the emissions were bang on, including the lambda reading with only advisory being a slight leak on the back box. It did have the P0170 fault code.

Any ideas would be gratefully received.