2009 Jeep Wrangler 3.8L V6 P0404 Code: Intermittent Check Engine Light and EGR Valve Diagnosis

I own a 2009 Jeep Wrangler with a 3.8L V6 engine. The check engine light came on initially without any noticeable engine performance issues. A diagnostic scan revealed the P0404 code, which indicates a malfunction in the EGR (Exhaust Gas Recirculation) system — specifically, a failure to properly seat the EGR valve or an issue with the pintle position sensor. I replaced the EGR valve as a first step, and for about one week, the P0400 code did not return. However, during an 80-mile drive, the check engine light reappeared at around 60 mph. Upon returning home, I scanned the vehicle again and confirmed that the P0404 code was still present. While driving locally, the check engine light turned off on its own, allowing me to resume normal operation. Notably, my Jeep is equipped with a factory remote engine start system (Chrysler OEM), which only functions when the check engine light is off — this has been a practical issue during troubleshooting. After clearing the P0404 code, I took another 80+ mile trip and observed that the check engine light came back on at approximately 60 mph again. The code reappeared, and it went away after local driving. This intermittent behavior — with no drivability issues — has led me to suspect a faulty EGR valve or an underlying sensor issue related to pintle positioning. I'm seeking advice from the community: could this be a bad EGR valve despite replacement? Are there other potential causes such as carbon buildup, wiring faults, or sensor inaccuracies that might trigger P0404 intermittently? Any insights on diagnosing or resolving this issue would be greatly appreciated.