No boost, backfiring, black plugs, need help!!!
 

I have a 2nd generation Rx7 that is dying on me, and I don't know why. The boost is gone, it feels like I'm driving a old civic or something, there is no thrust, nothing pushing you in your seat. The car also backfires a lot, not to mention turning plugs black like it's its job. Just wanting to know some possible problems, and descriptions of how to look for them? I have read some things online, that say it may be an open wastegate? Not sure where I'd find that? Or boost leak? Or a clogged cat converter?

Update: I took off the intercooler to see below it, tightened all connections, saw no leaks, nor improvement when I started the car, than took off the intake, the turbines on the turbo spin freely by hand. Than checked the wastegate on the turbo, moves pretty easily, doesn't seem stuck in any way, you can hear the spring on it. I'm running out of ideas, I don't know the car well enough to know if a small hose was off or missing. There is a piece, on the intake side of the turbo, which looks to be aftermarket from previous owner, and similar to the wastegate on the exhuast side of the turbo, it runs a rod to the exhuast side, but is covered by the turbo's heat sheild, so not sure what it does. It has a nut/bolt/nozzle thing, that adjusts the level of boost, and runs a hose to the intake side of the turbo, really not sure what this piece is.

Any input, solutions, information would be great, the car is high mileage, so not expected to be perfect, but was running a lot better than this a while back

well, it's hard to say from your description... but I would first perform a compression test. the motor could be blown

kind of sounds like you're talking about the twin scroll actuator.

wont make it run that poorly.

Check the precat. It may have fallen apart clogging the exhaust!

get the cat converter checked. My car was boosting only up to 3psi and it was in a shop for 5 days. They checked everything and on the last dat they checked the Cat Converter and all the mesh stuff inside it was melted. My boost just drop again today, so I think I melted my new Cat Converter again.

vac leak, I had the same problem when I first got my car, redid all the vac lines, new spark plugs n cleaned the fuel injectors, retuned tps etc you kno the routine!

but i'm still only boosting like half of what the car can really do,

because my stupid compressor is loose gotta tighten it back up when I get the chance