2G Car lags after couple minutes of driving

[Duxillec]

I just bought a 1999 Eclipse GST and it will start and drive fine but after about five minutes of idle or driving it will continuously lag as if it gets no fuel and my air fuel ratio gauges constantly goes from rich to lean fairly fast

I’ve replaced plugs, coil packs, cam sensor, and smooth ground contact points. Every once in awhile it’ll throw a misfire and cam sensor code

I’ve tested the fuel pressure and it seems to be fine. The car will just drop idle from 900-600 back to 9 and so on. It stutters out really hard when driving but doesn’t try to stall or bog out. It is a manual if that helps.

 

[pauleyman]

Please make a vehicle profile so we know exactly what you have and what is done to the car

 

[pauleyman]

Your profile lists no mods. Is this car bone stock? If you're not sure post some underhood pics and we can point out what is obvious.

 

[1990TSIAWDTALON]

Does the car still have a catalytic converter........???? (as they warm up they can stuff up the exhaust with back pressure if bad)
Fuel Filter new? (can show good pressure but can also slow the flow down as it is running if it is clogged)

 

[chrysler kid]

Could be a cracked exhaust manifold. Remove the heat shield cover and inspect for cracks