98 chevy lumina starts to go rough and lose power?

[Darrell]

at about 30 mph it starts to lose power and run really rough. it then gradually decreases power until you cant go faster than about 5mph. i just replaced both o2 sensors the catalytic converter some radiator hoses and the throttle position sensor. im about ready to stop dumping money into it i just want it to run.
well i just changed the oil about a month ago ill have to check the coil because i also less than a month ago got a new fuel filter

 

[bandit_60]

i was going to say the cat. converter but you changed it. i hate to tell you this but it sounds like it might be the transmission.

 

[Brian T]

try doing a tune up change coil and fuel filter and air filter they may stop the problem

 

[bgibby62]

hows the fuel filter?Once you shut the engine off and let it sit for 15 min..Does it run good upon restart?Check your fuel filter.

 

[Jay.Jay.]

From Wat Everyone"s Telling You,, Is A Little Off...
Ive Went Through Tha Exact Same Thing With A Trans-Am..
Came Out To Be, That I Had A Cylinder Leak.... Have A (Cylinder Compressioin Test) Ran On Tha Car... That Should Do Ya Right Up!!