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- Jun 2, 2012
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- canada
- Vehicle Year
- 1994
- Make / Model
- Ford
- Transmission
- Manual
1994 Ranger 4.0l 4x4 manual trans
I usually do clutch work myself but getting older and it is a PITA, so I bit the bullet and took truck to a local shop
Picked it up yesterday
Clutch is good but engine was running oddly after a little warm up, missing and no power, like running on 4 of the 6 cylinders
Then CEL(check engine light) came on, had this truck for many miles and many years and CEL has never come on.
code 173, O2 not switching rich on bank 1
Cleared code
So I figured they forgot to hook up one of the O2 sensors, "Y" pipe and O2s need to be moved to get at the clutch/trans
Had a look and both were hooked up
Cold it was OK but as soon as it warmed up missing and no power unless I was at Wide Open Throttle(WOT), then all cylinders came on line.
Went for longer drive, got CEL again, checked it after the drive
173 again and now 189
189, O2 not switching lean on bank 2
Rich on one bank and Lean on the other...................
I wonder............if they reversed the O2 sensors?
Sure enough, the connectors are the same, so left or right will plug in to either left or right, lol, never gave it much thought but I would think there would be a slight difference given the connectors locations, right next to each other on the back of the engine.
But when you buy O2s there is no left or right on most years so the connector would have to be the same
One wire color difference
grey/blue passenger side(bank 1)
red/black drivers side(bank 2)
They were reversed, swapped connections and all is well, runs great.
But I did clean the MAF, checked Fuel Pressure Regulator vacuum line and generally went over things on the engine, before the second code came up, lol
When engine is cold or at WOT computer ignores O2 sensors which is why I got all cylinders back
But during regular closed loop the Computer was cutting down fuel on one bank but O2 on that bank wasn't changing, so 173 not switching, Rich
And the other bank got Lean because fuel was being cut down, 189
So one side of engine was flooded and then other side starved, wonder it ran at all
I usually do clutch work myself but getting older and it is a PITA, so I bit the bullet and took truck to a local shop
Picked it up yesterday
Clutch is good but engine was running oddly after a little warm up, missing and no power, like running on 4 of the 6 cylinders
Then CEL(check engine light) came on, had this truck for many miles and many years and CEL has never come on.
code 173, O2 not switching rich on bank 1
Cleared code
So I figured they forgot to hook up one of the O2 sensors, "Y" pipe and O2s need to be moved to get at the clutch/trans
Had a look and both were hooked up
Cold it was OK but as soon as it warmed up missing and no power unless I was at Wide Open Throttle(WOT), then all cylinders came on line.
Went for longer drive, got CEL again, checked it after the drive
173 again and now 189
189, O2 not switching lean on bank 2
Rich on one bank and Lean on the other...................
I wonder............if they reversed the O2 sensors?
Sure enough, the connectors are the same, so left or right will plug in to either left or right, lol, never gave it much thought but I would think there would be a slight difference given the connectors locations, right next to each other on the back of the engine.
But when you buy O2s there is no left or right on most years so the connector would have to be the same
One wire color difference
grey/blue passenger side(bank 1)
red/black drivers side(bank 2)
They were reversed, swapped connections and all is well, runs great.
But I did clean the MAF, checked Fuel Pressure Regulator vacuum line and generally went over things on the engine, before the second code came up, lol
When engine is cold or at WOT computer ignores O2 sensors which is why I got all cylinders back
But during regular closed loop the Computer was cutting down fuel on one bank but O2 on that bank wasn't changing, so 173 not switching, Rich
And the other bank got Lean because fuel was being cut down, 189
So one side of engine was flooded and then other side starved, wonder it ran at all
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