A 1997 Jeep Wrangler developed a rough idle during warm-up after entering closed-loop operation. Unusual manifold-pressure readings drew attention toward the MAP sensor and engine computer.
What changed
In a follow-up, Gman reported replacing the upstream oxygen sensor, coolant-temperature sensor and thermostat. The engine then ran well. Reinstalling the old coolant-temperature sensor did not bring back the complaint, and the author attributed the improvement to the oxygen sensor.
What remains uncertain
Several parts changed during the repair sequence, and the thermostat was not reported as reverted. The account supports a reported improvement, but does not isolate every variable or independently prove one cause. The unusual MAP readings were not fully explained.
Reading the evidence carefully
A scan value is one piece of evidence. Record its units, operating conditions and plausibility alongside the actual symptom. When several changes happen together, distinguish a successful outcome from proof that a particular component caused it. This case is not a reason to disregard all live data or replace oxygen sensors on every vehicle with a rough idle.
Author follow-up · not independently verified
For information, not a diagnosis or repair instruction. A reported result may not apply to your car. Consult the manufacturer's guidance and a qualified technician.
How to use this information
This is an editorial interpretation of a public discussion. Replies, votes and an accepted answer do not prove a diagnosis. An author-reported finding or repair has not been independently verified by AI4Car. Illustrations are conceptual. Read the content limitations.
Credits & reuse
AI-assisted adaptation by AI4Car of the contributions below on Motor Vehicle Maintenance & Repair Stack Exchange. We shortened and reorganized the discussion, paraphrased its text and added educational context. These are reported experiences, not independently verified repairs. The contributors do not endorse AI4Car.
- Question: New MAP Sensor with wrong PID on scannerBy Gman · CC BY-SA 4.0
- Answer: New MAP Sensor with wrong PID on scannerBy Gman · CC BY-SA 4.0
This adapted article text, including AI4Car’s additions, is available under CC BY-SA 4.0. Reuse is permitted under that license with attribution, an indication of changes and ShareAlike. This notice excludes the separate illustration, site design and user comments. The source revision history remains available at Stack Exchange.
Illustration: AI-generated for AI4Car; a generic conceptual view, not a photograph of the reported vehicle or a manufacturer’s diagram. Content and licensing policy.
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