pulled codes but no help

[jhonda]

I have a 91mustang lx that is having some power issues. Sometimes it runs like a champ and others like a chump. I pulled the codes and came up with a code 67 with engine off and 12 while running, so these would have no effect on a power issue. It seems like I lose about 25 ftlbs of tq but the engine still pulls smooth. I have replaced the O2 sensors, engine coolant temp sensor, and the maf is clean. I am at a loss can anyone help me?

 

[5.0Droptop]

When is the last time it had a tune up, Plugs wires cap rotor, Check plug gap etc etc?

 

[jhonda]

around 20000thousand miles ago but you would think it wouldn't come and go if it was just the plugs and wires...etc Also have replaced the tfi module

 

[jhonda]

I also have a check engine light that flashes when driving sometimes, it has been doing this for at least 5-7 years. but again only got the two codes above

 

[jhonda]

Thanks for all the replys!!!