Thanks to some fine gentlemen here, I was able to ascertain that my 1993 civic with a 1.5L is throwing CEL codes of #43 (fuel system) and #1 (O2 sensor).

Now, it is my guess that the O2 sensor (code #1) is causing the other code.

The engine was just swapped. This is my work car, and I had to remove an old worn out 1.5 and replace with a junkyard motor with (supposedly) 100k. My old engine had 200k+.

Could the installer have done something to foul up the old sensor? Is my reasoning reasonable about the sensor causing the other other code?

I am seeking opinions.

Thanks!

Jim

 

Check whether the O2 sensor is unplugged or the wires are cut or damaged.

 

Update:

I changed the O2 sensor and all is well. Idle is better, CEL is gone.

Again, thanks to all who were kind enough to help.

Jim