car year and model:

1993 RX7 twin turbo(72k miles)

Problem:

hi, im from san diego and i just recently bought this rx7 from a dealership all the way from ontaria and drove it back to san diego a little bit past 100miles distance. The next day i re-checked the engine and decided to replace the ugly looking hose that is1" in diameter being kinked in between my turbo intake and engine. i replaced it with a hose that is a little bit smaller than 1" and after that i decided to do a test drive.fuel is low so i was planning to go get some gas.not even 1 mile away from my house i heard a "pop" sound coming from my engine bay and then my car died with check engine light and battery light with coolant and oil light on. the normal light that will turn on when you are about to start your car. i assumed that i just run out of gas.so i went to the gas station and bought some gas(91 gas) and my car started back up and i heard another "POP" sound.disregarded the sound and just decided to go back home and re-install the 1" hose back. after re install started back up the car did a test run and still stalls.so i decided to go to mazda dealership(i know thats like one of the "no no" for rx7 but they got an rx7 specialist) but the specialist is not there till the next day.so decided to drive back home. On my way home car stalled at least 5 times also its having hard time accelerating. normally at 4krpm the car would be already at 60mph but its only at 40mph.so i decided to observe the car in idle.based on my observation car is having a bad idle (1k-1.5k rpm) and sometimes its fluctuating up and down. so i decided to check the idle control by the throttle body just like the manual said "screw all the way and then unscrew 1/4-1/2 turn.did that still bad idle.i dont have the right tool to check my TPS.so i just let it be.and then i just let my car on idle for like 5mins.and i decided to hop on check observe my tachometer. i stepped on my brake and my gauges light started to flicker and i stepped on my brake harder and my car just stalled.i was assuming that this is a big vacuum leak.i need some help.i dont know where in my engine that pop sound came from. what could blow up or pop when you replace the 1" hose in your engine?? im not gonna be able to troubleshoot the car till i got back from business travel. did my home work most of em saying that its a vacuum leak.and some says its a blown apex seal(hopefully not).need some help please. Thanks!