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I'll try to make this entertaining.
A few weeks ago my father in law and I were heading to his shop to replace the timing belt on my 93 Ranger. It was about an hour drive out to get him, then 10 minutes to get to the shop. During the 10 minute excursion the CEL came on and went off about a minute later. At the shop we hooked up a code reader and it came out empty handed, saying everything was fine. I normally didn't take the truck on many > 30 minute drives and had never had a CEL on before.
Yesterday I drove the lightly-loaded Ranger nearly 1000 miles from NC to IA. About 40 minutes into the trip the CEL came on. I found that turning off the engine and back on would reset the light so I didn't deem it too important, and after the initial encounter it didn't come on for about 6 hours of mountain driving. Got into the plains of Ohio and it came back on. Reset the engine to clear the light mid-drive, start her back up, continue driving. This happened about 50 times! The truck was otherwise driving during the and I didn't "feel" any problems.
There was no pattern, unfortunately. Sometimes it'd come on when I hit the cruise control button, some times after a bump; some times it'd take 25-30 minutes to come on again and sometimes just a few minutes. Over the last 30 miles or so it was coming on every 5 miles. It came on both while running on cruise and while manually controlling the throttle, although it never seemed to come on below 50MPH.
This morning I ran the tests... not too helpful.
KOEO: 111
CM: 172
KOER: 111
That's it. I've done tons of a searching and it looks like most people have something in addition to the 172. Resistance between the power and ground terminals of the O2 sensor is 5.8 ohms, which the Autozone online manual says it should be. Checked the heated/cool air door before the filter, that works fine. I seafoamed a few months back so the injectors should be fine. I sprayed out the MAF sensor about a month ago with MAF cleaner should that should be good. I don't see any apparent cracks in the exhaust manifold (although it is admittedly pretty rusted).
So, any thoughts on what else I should be looking for? What's really puzzling is the truck otherwise drives fine (at least, it hasn't driven any different for the 4 months I've owned it), gets between 21-26 MPG which seems to be expected... I'm not sure where else to look.
A few weeks ago my father in law and I were heading to his shop to replace the timing belt on my 93 Ranger. It was about an hour drive out to get him, then 10 minutes to get to the shop. During the 10 minute excursion the CEL came on and went off about a minute later. At the shop we hooked up a code reader and it came out empty handed, saying everything was fine. I normally didn't take the truck on many > 30 minute drives and had never had a CEL on before.
Yesterday I drove the lightly-loaded Ranger nearly 1000 miles from NC to IA. About 40 minutes into the trip the CEL came on. I found that turning off the engine and back on would reset the light so I didn't deem it too important, and after the initial encounter it didn't come on for about 6 hours of mountain driving. Got into the plains of Ohio and it came back on. Reset the engine to clear the light mid-drive, start her back up, continue driving. This happened about 50 times! The truck was otherwise driving during the and I didn't "feel" any problems.
There was no pattern, unfortunately. Sometimes it'd come on when I hit the cruise control button, some times after a bump; some times it'd take 25-30 minutes to come on again and sometimes just a few minutes. Over the last 30 miles or so it was coming on every 5 miles. It came on both while running on cruise and while manually controlling the throttle, although it never seemed to come on below 50MPH.
This morning I ran the tests... not too helpful.
KOEO: 111
CM: 172
KOER: 111
That's it. I've done tons of a searching and it looks like most people have something in addition to the 172. Resistance between the power and ground terminals of the O2 sensor is 5.8 ohms, which the Autozone online manual says it should be. Checked the heated/cool air door before the filter, that works fine. I seafoamed a few months back so the injectors should be fine. I sprayed out the MAF sensor about a month ago with MAF cleaner should that should be good. I don't see any apparent cracks in the exhaust manifold (although it is admittedly pretty rusted).
So, any thoughts on what else I should be looking for? What's really puzzling is the truck otherwise drives fine (at least, it hasn't driven any different for the 4 months I've owned it), gets between 21-26 MPG which seems to be expected... I'm not sure where else to look.
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