Passed MOT but...

everything fine for MOT but the tester has gone and altered the idling or mixture,  What should I do? the car was running lovely, after I had a bosch centre set it up for me about 2 years ago, now it idles at 500rpm and is quite embarrasing in traffic/car parks. I've a right mind to go down there and get annoyed but this won't solve anything, it's just hassle to go back there and get it sorted when really I shouldn't have to if he'd left her alone in the first place!!! anyone else had a similar experience of this kinda thing?

Not had problem myself, but think you should go back to them on principle.

I think if they test to the letter of the law they shouldn't adjust/touch anything. You'll always get the 'goodguy' who did a minor tweak to get the car through first time for you, which you appreciated, but if he's messed it up then get them to sort it!

Turn the screw clockwise until the rev counter shows 900-1000 rpm.

Thinking about this logically he's either tweaked the idle screw or the mixture to reduce the emissions.

1. If he touched the idle then just wind it back out again.

2. If he touched the mixture, let's assume he set it correctly, then you need to move the idle screw to compensate.

If he's set the mixture wrong then you need to show him some Essex style retribution.

Peter.

Think the safest way is if you make a note of where the idle scew currently is and what the car is idling it then turn the idle speed up until it is upto what it used to be, drive it arround and if it doesnt feel right reset the idle and turn the c02 up which is probably what he has done