Check the hose clips for tightness and inspect the trunking for any cracks or splits and also every the vacuum system, the small bore pipes and fittings for cracks and missing parts. The best showing off to locate a leak is to have the engine dealing out and hot and next spray lighter gas /propane or brake cleaner roughly speaking each joint in turn. If the engine rev s stirring you ve found your leak.
Its moreover worth getting the fuel pressure checked as if this is low due to a blocked filter or faulty regulator or even a under the weather pump will all result in insufficient fuel monster delivered to the engine. Might as a consequence be worth cleaning out the idle promptness direct motor / valve as these acquire clogged going on considering carbon and some brake cleaner washed through helps clear things off.
I don't have any check engine lights unless I unplug the MAF sensor. bearing in mind the MAF is plugged in subsequently the car will stall unless I put my foot upon the accelerator. There is then an intermittent popping sealed coming at idle.