In the last couple of weeks the car would chug and not want to speed up at times but then at times it would drive perfectly fine. Then it started to get worse and it would hesitate as it sped up.

All this time I'm thinking it's either a coil pack or the spark plugs that need to be replaced because i had replaced 2 of the plugs and they looked almost original and I didn't have the money at the time to replace any of it so i let it slide for until it reached this point.

Well a few days ago it really started to act up and the check engine came on and started to flash when i try to accelerate but the car now won't go over 30-40 mph and if I push it it will basically lose all power and slow down to about 10 mph before it'll let me speed back up.

Those are the symptoms. The codes I've had vary a little. The 3 that pop up all the time are p1000 drive cycle not complete, p0172 bank 1 to rich, p0174 bank 2 to lean, and the ones that vary are misfires. I've gotten a mis for cyl 1, 3, and 4, at different times and sometimes together. also forgot one it was a body code something about the battery but i can't remember what it was

I decided to looked at the engine and try and diagnosis what was wrong. I focused on cyl 1 because that one has come up the most and its the easiest to get to. What i did was unplug it while the car sat at idle to see how much it changed compared to the other cylinders and in my opinion it didn't change as much as the others I tried. So I switched plug and coil pack from cylinder 2 because it was right there and cyl 1 continued to seem weak. As a matter of fact it actually made the car idle/run worse.

Something I thought I should mention is if i where to push it and the car did in fact speed up the motor would rev all the way to say 3000-3500 before it shifted gears and it would make kinda a metal clanking noise almost like the belt tensioner was worn out.

The only advice that has made sense I read somewhere saying is a clogged cat could be the problem other then that i am stumped. Does anyone else have any ideas or point me in a good direction?