What This Sensor Does
The 4088712 is a thread-in exhaust gas temperature sensor with an M14 x 1.5 body and a 2-pin connector. It sits in the exhaust or EGR circuit and reports gas temperature back to the ECM. That reading feeds EGR control and aftertreatment decisions, so a bad signal does not stay a quiet problem for long.
Failure is usually heat and vibration driven. The high-temperature tip degrades and the sensor starts reporting drifted or erratic values. Sometimes it opens outright and the ECM sees an out-of-range circuit. Connector corrosion and chafed pigtails cause the same symptoms, so check the harness before you condemn the sensor.
Symptoms a driver notices: a check engine lamp, derate, or regen behavior that does not match how the truck is being run. Symptoms a tech notices: a temperature value on the reader that stays pinned, reads ambient with a hot pipe, or bounces while the engine holds steady load.
Why 4088712 And 050641 Cross
050641 is the PAI Industries number for the same sensor position as the Cummins 4088712. Aftermarket suppliers assign their own catalog numbers, but the physical part behind them is built to the same interface: M14 x 1.5 thread, 2-pin connector, and the same temperature-sensing element characteristics the ECM expects.
That last point matters more than the threads. Two sensors can screw into the same boss and still read differently. A cross only holds when the resistance-to-temperature response matches, because the ECM converts raw signal to a temperature value with a fixed table. Get that wrong and you trade a dead sensor for a lying one.
Treat the cross as a starting point, not a guarantee. Numbers are listed for identification only. Confirm by reading the number stamped or tagged on the sensor you are pulling, or verify against your engine serial number before you order.
Check Before You Order
Pull the old sensor and read it. Thread size, connector count, and pigtail length are the three things that bite people. This part is M14 x 1.5 with a 2-pin connector — if what comes out of your engine is anything else, stop and verify against the engine serial number.
Note the position it came from. These engines can carry more than one temperature sensor in the exhaust and EGR circuit, and the fault code tells you which circuit, not always which physical location. Trace the harness before you order so you replace the sensor that actually threw the code.
4088712 Cross-Reference & Interchange Numbers
These manufacturer and aftermarket numbers commonly cross-reference to 4088712. Use them to identify the part — then confirm the exact fit by VIN or the number stamped on your old unit before you order. An interchange is a starting point, not a fitment guarantee.
| Brand / Line | Cross-Reference Numbers |
|---|---|
| PAI Industries | 050641 |
Frequently asked questions
Will 4088712 fit my ISX without checking anything?
No. Fitment is confirmed by your engine serial number or by the number on the sensor you remove, not by the engine family alone. Cummins ran different sensor configurations across build ranges. Pull the old part, read the number and check the thread and connector before ordering.
Is 050641 the same sensor as 4088712?
050641 is the PAI Industries catalog number that cross-references to the same sensor position. The numbers are listed for identification only. Physical interface is M14 x 1.5 thread with a 2-pin connector on both. Confirm against your old part before you commit.
My code came back after replacing the sensor. What now?
Check the harness and connector first. Chafed wire, corroded pins or a loose lock will produce the same open- or out-of-range circuit code as a failed sensor. Also confirm you replaced the sensor in the circuit the code names — these engines carry more than one exhaust temperature sensor.
Not sure it fits? We check before you pay.
Run your VIN and we’ll match parts to your exact truck, or call the counter — a person who knows trucks verifies fitment by OEM number before the order ships. No wrong-box returns.
More cross-reference guides
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Every part below is a Premium Quality aftermarket Direct Replacement with published OEM cross-reference numbers, a 6+ month warranty and same-business-day shipping from Tacoma, WA. Not sure it fits? Run your VIN — or call and a person who knows trucks will verify fitment before you pay.