I recently swapped a 97 Integ B18b into my 93 Sol Si. Everything appeared to go smoothly and for the first 10k miles I was very happy with the swap. All of a sudden weird things are beginning to happen - -- Power is gone - with the AC on I have absolutely no tire spinning torque - even if I rev up first. Car can make it to 80, but no where near as fast as the D16 could. -- Severe idle hang - for the first 5-10 minutes after startup the engine tachs itself at around 3k and will not come down. -- Startup - the motor fires up before completely turning over - its like you can almost breath on the key to get it running, then the idle is choppy. -- MPG - plunging - went from a steady 32mpg to a weak 29mpg now I'm watching the numbers drop tank to tank. Currently at 25mpg. There have been two catastrophes that occurred at about the same time - I don't think they were the causes, but they definitely didn't help: Spark plugs mysteriously drown - drove thirty miles and noticed sparks under car before I realized what happened. AC Belt snapped - ripped apart both other belts and ripped timing belt off of sprocket. Four new belts and re-timed. New belts, fuel filter, distributor, ig coil. I'm told that the sparks from the drowned plugs was from a melted cat - still haven't replaced. Money's tight right now and I cannot afford to loose the commuter so I'm hoping to narrowing it down to one solution. I'm planning to replace the plugs, wires and cat here soon. I've been toying with this for weeks now, I'm seeking possible other causes or suggestions.