mcduff0192

ok heres my story. i got a 94 z28 auto. i was driving on the highway and completly lost 4th. then slowed down to 35mph to get it home safe. noticed it didnt have 1st and 4th. so i read that it was a shift solenoid. changed it out and now shift all gears but now when i drive it it acts weird. at start up it acts fine. then when i drive around and it starts warming up it starts shaking and rattling and if it sits for like 30 seconds it stops. seems like it gets pressure or opens up a little bit and engine light comes on. but when i shut car off and start again it repeats the process. i checked what the codes are for the light and it is left o2 sensor failure and o2 sensor lean and also egr failure. engine has egr delete on it. would this problem just be o2 sensor or a bigger problem