Slight Shaking on idle, air leak?

[moukie]

Hi! Hoping someone can help. Had the timing belt replaced last year by a reputable specialist. I have noticed the car shaking a bit on idle and there is a slight misfire logged on cylinder 4. Seems to be fine under load just on idea. Other issue is pulling away in 1st there sounds like an air leak. I have done all the usual things, replaced plugs, coil packs, Diverter Valve, PCV. Anyone experienced soemthing similar... any pointes. I did wonder about the injectors....

[pudding]

That does sound like injectors.  Misfiring at idle is when you notice it the most.  If there's a big enough air leak to cause problems, it usually flags a 'system too lean' code.