So for two weeks now my 96 4.0 has had issues accelerating. When it’s cold there’s virtually no issues. Generally any heavy throttle will feel like it bogs down the engine and causes it to hesitate. This gradually gets worse the longer I drive it at one time until the point where I can barely give any throttle before it won’t rev up any more. We’ve had the transmission checked, replaced plugs and wires, replaced the throttle position sensor, and upstream O2 sensor. I’ve gotten the code P0171 for lean engine, and codes for misfires in cylinder 1, 2, 3, and 6. Any input would be great appreciated.
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Acceleration Issues
- Thread starter colets23
- Start date
- Location
- Minneapolis, MN
Follow the OBD trouble codes for your trouble shooting. What brand of O2 sensor was installed ? The Jeep 4.0L does not play well with Bosch O2 sensors, you should be using NTK brand O2 sensors.
Test the Coolant Temperature Sensor.
Most Cherokees have a cracked exhaust manifold that lets in fresh air that the O2 sensors see a Lean Condition.
P0171 JEEP - Fuel System 1/1 Lean
Possible causes:
•Exhaust gas leaks
•Intake air leaks
•Faulty front heated oxygen sensor
•Ignition misfiring
•Faulty fuel injectors
.
Test the Coolant Temperature Sensor.
Most Cherokees have a cracked exhaust manifold that lets in fresh air that the O2 sensors see a Lean Condition.
P0171 JEEP - Fuel System 1/1 Lean
Possible causes:
•Exhaust gas leaks
•Intake air leaks
•Faulty front heated oxygen sensor
•Ignition misfiring
•Faulty fuel injectors
.
