Need Help With Code 42

[TrickStang37]

basically, the car begins to hesitate when i gas it. it idles PERFECTLY though. it will hesitate even at WOT. not always though sometimes it runs perfect too. i cleaned out the salt and pepper plugs, the spark plugs are new, changed them twice actually, spark plug wires are perfect (new), new cap (3 different ones), new rotor (2 different ones). Put a new TFI, same thing. no vacuum leaks. if it were a sensor, what sensors work during WOT? or maybe coil? maybe pick up in distributor? how do I check those? cleaned MAF, o2 sensors are new, ran fuel pressure gauge, fuel pressure stays perfect during hesitation.

[mpj76]

I don't know what code 42 is, but my car had the exact same symptoms as yours. It ended up being my battery cable! It had a small crack in it where it started to oxidize. It was the one that ran from the terminal to all that electrical stuff attached to the fender wall. I swapped it out with a larger gauge while I was at it. Problem gone. It will be worse if you have an MSD box - they're very voltage sensitive. Don't expect to see your voltage needle flicker if this is the problem. By it's nature, this problem was very intermittent, and varying in degree. At least it's an easy fix. I'm also running the 3G.

[Coupe50h]

Dang, your car is a gt but weighs as much as my coupe?

hey man, how does it run in the higher rpms? if it pulls hard after the hesitation, then we can rule out the coil, although i seen my friends 93 gt get two bad coils in a row, and it caused "spark scatter" and we couldnt figure it out?
we replaced the tfi, cap, and all you listed above, also his msd coil wouldnt work right, it ran better with a stock coil......hope someone can help you more than this.