Dont lose me to the Japan cars fiero wont run

[cool man 1974]

Hello i just got a arizona car no rust fiero 1985 with a 2.5L with 57,000 miles 5 speed was driveing check engine light came on and no power it would surge and idle up and down got it home pulled the code 44
replaced the 02 sensor unpluged the battery reset code now it whont run
replaced
O 2 Sensor
cap + Roter
Wires
4 New spark plus gap at .060 acdelco
air filter
pvc valve
fuel filter
iac
m.a.p. sensor
egr
breather valve
rebuild throto body fuel injecters work
grounds are all good
cant run so i had it tow to a mechanic they had it for 4 weeks
check all vac lines no leak the fuel pump has pressure
replaced a used ecm same thing replace coolant temp sensor
car run but if you un plug it car runs good no loss of power plug it back in
car stalls new coolant temp car runs bad even the mecanic cant figure it out
can you

 

[Oreif]

Since it's the 2.5L, Check the timing gear. They can lose a tooth and jump timing.
A clogged catalytic converter can trip the O2 code and then make the car not run or run badly.

 

[cool man 1974]

Thanks man final some one but the cats ok its still there in the shop
il tell them to look at the gears maybe a chiped missing tooth causing off timing Thanks man

 

[cool man 1974]

They found and answer a Bad Fuel pump after 36 days in the shop it was a Bad fuel pump