Chrysler Repair: mis-firing/idles rough in reverse:93 3.3L van, lean mixture, exhaust gases

Question
HI. I have a 93 town and country van 3.3 and I just changed the O2 sensor and throttle body sensor do to code being 52 and 23 but still having idle and miss fire when gas tank is half full. husband looked at fuel filter too it's fine. what can it be and could it be as easy as new spark plugs ,there about year old.

Answer
Hi Cynthia,
I would suggest disconnecting the battery for a minute or so, then restart the engine and drive it a bit, then re-read the codes. You will get a 12 (because of the battery disconnect, which will erase all the old codes) and of course a 55. But then see what is else comes out again. The 23 code was a misreading, because there is no 23 code. The 24 code, it that is what it was, is indeed for that sensor. But maybe it is something else.
Also, I would check the egr valve. It is possible that your egr valve is sticking slightly ajar which will cause the engine to falter/stop at idle speed after slowing down. The valve is located near the throttle body air intake at the end of the engine, mounted in pipe that recirculates exhaust gas from the rear cylider bank exhaust pipe back around to the intake manifold. The exhaust gases have some fumes that can plate out a crud on the valve stem and thus keep it from closing tight when you are at idle. That makes for a too lean mixture so the engine stalls. The valve proper is mounted horizontally with the stem visible in a space between the body of the valve mounted on the pipe and the round top of the valve which is flanged and so if you look carefully you will see a metal rod (stem of the valve) with a slot around its circumference. You can take the tip of flat blade screwdriver and insert it in the slot and then lever the valve back and forth to check if it is moving freely (against spring action in one direction) or not. If it doesn't seem to close easily with the help of the built-in spring, then I would spray the base of the stem with solvent from a pressure can (such as WD-40 or carb cleaner) while moving the stem back and forth.  Then see if that solves the issue.
Roland