ok need help with a friends 95 z28. about a year and a half ago a comp cam and longtubes were installed. it ran ok for about a month and then started running like ****. basically when the car gets to normal operating temp it spits sputters and runs like hell, even dies occasionally. so far the parts replaced have been numerous o2 sensors, map sensor, mass airflow, plugs, wires, opti, iat, 2 computers including one with a custom tune and a knock sensor. it runs find when its cold. btw it runs a little better when knock sensor unplugged, but still ****ty. its been in several shops including a chevy dealer. i dont think its anything internal. help

 

Have you tried the EGR yet? If it's only doing it when it's warm could be that?

 

the egr is blocked off with plates. also has new fuel pump

 

bump

 

anyone?