sorry a mustang ? need help tho

[fastlikeanascar]

My headers were glowing Red after about 2mins of idling so I hollowed out my cats " totally legal in CA :biggrin: " but they are still turning red but just a little bit now... I have yet to drive the car because I'm trying to get everything worked out.

any Ideas on what this can be.

 

[KL Mallender]

Low working compression(ie: less than 8.1cr + larger duration cam) combined with retarded ignition timing are the usual culprits, overly rich fuel mixture would also be worth looking at, bottom line is that you are not completely burning the mixture inside the engine, it's continuing to burn in the pipes.

Kevin.

 

[87granny]

Leaking fuel injectors will do this to