I have an 83 Z28 with the Crossfire 305 and am having some problems. I have posted before about my car running lean but now there are more issues. I run the engine codes and get a code 44 and a code 42. My book tells me that the code 44 is a lean condition on the O2 sensor and i have an idea that the fuel pump may be bad. Any other ideas????? Also the book says that the code 42 is the EST. The only thing that I could figure that means is the Electronic Spark Timing?? I honestly have no idea! Any help with what this code means and what i should check for it would be greatly appreciated. I did notice that at times when the light comes on i can smell gas and there is a bad hesitation. Thanks in advance for any help!!!

 

I don't generally advocate replacing parts without testing...but a lean condition (code 44) and smelling fuel (rich condition) would indicate the O2 sensor is malfuntioning...probably due to age.

But. clear the ecm (disconnect power to it for a few minutes) reconnect it, and test drive it. See if the rich smell is still there, and if it resets a 44...if so, I'd think O2 sensor needs replacement.
Code 42 occurs when EST Btpass is disconnected to set timing, so could be faulty connection or something else...do a search on TPI forum and here too for code 42, the diag has been posted lot's of times.