Can anyone help me figure out what is causing the code 42? For some reason, it just all of a sudden threw the code yesterday as i was getting ready to leave the track. Don't have any clue as to why. I am wondering if it is possibly because of the MSD coil that I put on. Any help would be appreciated. TIA.

John

 

A code 42 just came up on my 88 T/A....I have a check engine light,as well as the car is running in back up limp mode...scanned it the other day...the suggestions from the scanner was either a faulted est wire,bad ignition module or faulty ECM...the car starts and runs but has no power...the est wire looks good from what I can tell,and the igntion has been fine does not miss even in limp mode...so I'm replacing ECM..

Does your car run rough?

 

No...my problem turned out to be that the EST wire was not completely plugged in, so it was staying in limp mode.

 

Good.....wish mine would have been that easy..