Check the hose clips for tightness and inspect the trunking for any cracks or splits and as well as all the vacuum system, the small bore pipes and fittings for cracks and missing parts. The best quirk to locate a leak is to have the engine dealing out and hot and subsequently vaporizer lighter gas /propane or brake cleaner with reference to each joint in turn. If the engine rev s in the works you ve found your leak.
Its then worth getting the fuel pressure checked as if this is low due to a blocked filter or faulty regulator or even a poorly pump will every repercussion in insufficient fuel creature delivered to the engine. Might moreover be worth cleaning out the idle keenness govern motor / valve as these get clogged happening behind 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. once the MAF is plugged in then the car will stall unless I put my foot on the accelerator. There is then an intermittent popping sealed coming at idle.