Chrysler Repair: 1996 Chrysler New Yorker: code P0171, coolant temp, chrysler new yorker

Question
Error Code P0171.
I found #5 Sparkplug Tube Full of oil.
Replaced Tube Seal,all plugs,wires and coil pack.
Now after running for about 20 min. error code comes up.
Any Ideas?

Answer
Hi Bob,
Check for exhaust system leaks between the engine and the sensor (e.g. exhaust manifold leaks in this case on the right side. Then check that coolant temp sensor resistance drops to 700 to 1,000 ohm when the coolant reaches operating temperature according the gauge. The accuracy of the MAP sensor might be tested but that is generally done with a DRB. Check that the inlet air temp sensor resistance is dropping also as the engine warms, though it won't get to as low a value as the coolant sensor, I suspect. The O2 sensor is another possible culprit, not being accurate measure of the mixture of the exhaust.
I don't think it is related to the repairs that you did.
Roland