This car had starting issues. The previous owner replaced the fuel pump, fuel pressure regulator, clutch, clutch master assy. I drove it but anytime I accelorated at a rate higher than 2500 rpms it would shutter and bog down. I got a diagnostic and replaced the O2 sensors. No luck. I thought maybe the cat was clogged so I cut it out and put a strait pipe in its place.it seems to get better air flow now but it still shutters every so often. Next I replaced the fuel pump and neutral safety switch. Now I just got the timing chain kit with new chain, intake sprocket, exhaust sprocket, crankshaft sprocket tensioner, and guides. Now my acceloration is much better but I still have the starting issue. It turns over but no fire. Takes two or three times of doing this paired with feathering the gas to get it to get fire. Even then it hovers around 150 - 200 rpm for about 15 seconds befor it will idle at the normal range. I smell exhaust fumes in the car but that was happening before I put the strait pipe on so I'm assuming there may be something else wrong with the exhaust. The car has 141xxx miles on it. I need help figuring this out

 

A year and engine size would be helpful. Do you have any current codes?

 

It's a 2005 2.2 ecotec DOHC. I don't remember the code that referred to intermittent misfires. And there was a p0172. Running rich

 

2 door 5 speed. I'm not 100% whether or not that makes a difference.