Help With Computer Code 173
Another forum on this website (SuperDuty trucks) suggested that I post my questions on the 385 series forum, because several 460 experts were in this forum.
I just used a Sunpro scanner on my 1993 Pace Arrow motorhome with the F53 chassis, 460 engine. The "check engine" light was coming on, and staying on, after about 30 minutes or 30 miles.
I had no codes during the KeyOnEngineOff test.
I had a code 173 during the KeyOnEngineRunning test. The Sunpro book says a code 173 is "Heated exhaust Gas Oxygen sensor voltage signal indicates rich (Bank #1)".
I already suspected that the engine was running rich, beacause it spits out black "goop" when cold and the fenderwell where the exhaust exits is somewhat blackened from the exhaust. But the engine runs fine and idles smooth as a kitten.
Any ideas on what to look for to make the code 173 go away?
The 02 sensor, catalytic converter and ECM (subjects of a Ford recall), EGR valve, plugs/wires, dist cap/rotor, fuel filter, air filter, breather filter, and PCV valve are all new.
Could my Code 173 (and my symptoms) be related to timing that is too advanced or too retarded? I'm not familiar with timing adjustments and do not have a timing light.
My son, who is an excellent mechanic , (he is in USAF and works on F-16s) says he can check/adjust the timing by ear? But he also says that serious engine damage can be caused by incorrectly adjusting the timing. This has me nervous, because I can't afford a new engine.
Thanks in advance for any thoughts on how to narrow the focus of my search.
Tom Norman


