rpm drops unexpectedly during acceleration

Asked by Feb 24, 2017 at 06:28 AM about the 2000 Subaru Legacy GT Wagon

Question type: Maintenance & Repair

I have a legacy 2000 wagon 5 speed manual shift. I recently noticed when at
2nd gear 2800 rpm when accelerating with pressed gas pedal, the rpm drops
unexpectedly to 2000 rpm, with power loss. This also happens at 3rd gear at
the same rpm. The vehicle acts like power is cut when the rpm drops. The
rpm picks slowly afterwards. What could be the problem?

8 Answers


If the check engine light is on have the vehicle scanned for trouble codes, then write them down and post them back here for further assistance. I suspect there may be a problem with the throttle positioning sensor.

DTC P0325.. That's the error code


P0325 - Knock Sensor Circuit Malfunction...Possible causes; Faulty knock sensor, Knock sensor circuit poor electrical connection, Knock sensor harness is open or shorted, Faulty Engine Control Module (ECM)...The P0325 code means that the Knock Sensor is not working properly. Problems with the knock sensor will not cause an engine performance problems. Replacing the knock sensor usually takes care of the problem.


If the knock sensor caused the timing to be retarded it could reduce engine power.

Thanks guys for your help. I've replaced the knock sensor, but problem still persists. The check engine light is not coming on though, no error codes present.


If there is a EGR Valve on there, take it off and clean out the carbon from the EGR center pental and may want to take it to a auto parts store to see if it works. It is on a spring and should move in and out. Also clean out the port in the intake from carbon also. Make sure and put a new gasket back on.

2 of 2 people found this helpful.

Yeah, I'd spray clean the EGR and PCV, and then think about the MAF sensor connection and its plenum seal.

Thanks guys. I replaced the MAF, and air filter which was dirty. My clutch was also worn out and fixed in a new clutch set. Performance now back to normal. I really appreciate your feedback.

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