Help With Computer Code 173
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Help With Computer Code 173
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.
Thanks in advance for any thoughts on how to narrow the focus of my search.
Tom Norman
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.
Thanks in advance for any thoughts on how to narrow the focus of my search.
Tom Norman
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Monsta: The 02 sensor is virtually new. It's about a month old, with about 750 miles driven since it was installed. I should add that the engine has 48K miles on it. No, I have not checked the timing---I thought the timing was computer-controlled?
n578md: Not sure if my motorhome engine has a MAP sensor, but I'll take a look.
Thank you both for your inputs!
Tom Norman
n578md: Not sure if my motorhome engine has a MAP sensor, but I'll take a look.
Thank you both for your inputs!
Tom Norman
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Monsta: Oops!
You are correct. It does have a dist cap/rotor. Therefore I can have the timing checked and adjusted as needed. (I don't have anything to check it with.)
Showing my ignorance on timing issues---is running rich caused by timing that is too advanced or timing that is too retarded? What is the correct (best) timing for my engine?
Anything else I can look at before I drive the rig to visit my friendly local mechanic?
Tom Norman
You are correct. It does have a dist cap/rotor. Therefore I can have the timing checked and adjusted as needed. (I don't have anything to check it with.)
Showing my ignorance on timing issues---is running rich caused by timing that is too advanced or timing that is too retarded? What is the correct (best) timing for my engine?
Anything else I can look at before I drive the rig to visit my friendly local mechanic?
Tom Norman
Sit. Stay.
Joined: Oct 2001
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From: Washington State
Retarded.
No...not you! The timing!
Not to pawn your questions off but try the 385 series forum. There are many 460 gurus who hang out down there who can better answer you timing spec questions.
No...not you! The timing!
Not to pawn your questions off but try the 385 series forum. There are many 460 gurus who hang out down there who can better answer you timing spec questions.
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Monsta, thanks for the advice. I just cut/pasted my questions and posted them on the 385 series forum. With any luck somebody in that group will have already slayed this dragon!
Again thanks!
Tom Norman
Again thanks!
Tom Norman
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My son and I just resolved the code 173 that we got when we hooked up our code scanner. Turned out to be a bad fuel pressure regulator on the injector rail. The rubber diaphragm inside of it had failed, allowing raw gas to be sucked via the vacuum line into the intake. We just finished putting in a new one, Sorensen part number 800-127, from Advance Auto Parts ($23.99). Our code 173 is now gone! No codes at all. Plus our engine now runs smoother than it has ever run.
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