2005 Nissan G35 P0340 Code: Loss of Power and Stalling on Highway - Diagnosis and Fix

Hi everyone, I'm currently dealing with a recurring issue on my 2005 Nissan G35 Sedan (Automatic). The problem started about a month ago, and I've now confirmed two P0340 Diagnostic Trouble Codes (DTCs) using a basic code reader. Background: - Vehicle: 2005 Nissan G35 Sedan, Automatic transmission - Mileage: ~80,000 miles with consistent service history - Purchased approximately 9 months ago Symptoms: - While driving on the highway (around 75 mph), I experienced a sudden loss of power — it felt like the car was both breaking and stalling simultaneously. - On one occasion, the vehicle briefly stalled for a fraction of a second, then resumed normally after a moment. - After arriving at my destination, I turned off the engine for about 10 minutes. Upon restarting, three warning lights illuminated: Service Engine, Slip, and VDC Off. - The car started slowly at first but eventually ran fine during short drives. I checked all fluid levels (oil, coolant, brake) — everything appeared normal. I performed a recent oil change (~3,00 in the past 3000 miles), using full synthetic oil. The oil looked dirty but not severely degraded. After driving back to work, I noticed that the stalling behavior occurred again after about 10 minutes of highway driving. At that point, the Slip and VDC warning lights also came on. I used a coworker’s basic code reader (with only 'Read' and 'Erase' functions) to confirm two identical P0340 codes. After erasing them, I took a backroad route and limited speed to below 45 mph to avoid triggering the codes again. My plan is to replace both sensors related to the P0340 code tomorrow. I’ll update this post with follow-up results after the repair. Any insights or experiences from owners of 2005 Nissan G35s with P0340 issues would be greatly appreciated! Thank you in advance for your help.