2020 Nissan Pathfinder Engine Problems

I own a 2020 Nissan Pathfinder with approximately 55,000 miles. The vehicle repeatedly failed Indiana emissions testing because the oxygen sensor monitor would not set to “ready,” despite multiple complete drive cycles and no check‑engine light or stored fault codes. A local shop performed diagnostics and found no issues. They reported that another 2020 Pathfinder came in the following week with the exact same problem. My vehicle was ultimately sent to a Nissan dealership, where they determined the upstream oxygen sensor had failed in a way that prevented the ECM from running the emissions monitor, yet did not trigger any diagnostic trouble codes. The repair required full sensor replacement at a cost of $1,450, not covered under warranty. The failure mode is concerning because: • The vehicle gives no warning to the driver. • The ECM blocks emissions readiness indefinitely. • The issue appears to be occurring in multiple 2020 Pathfinders. • Owners cannot legally renew registration without passing emissions. This may indicate a defective oxygen sensor or ECM logic issue affecting 2020 Pathfinders. I am filing this complaint so NHTSA can track the pattern and determine whether a broader defect investigation is warranted. Vehicle Details: • Year/Make/Model: 2020 Nissan Pathfinder • Mileage at failure: ~55,000 • No warning lights, no stored codes • Emissions monitor would not complete • Dealer confirmed sensor failure and replaced part Safety Concern: A failed emissions component that does not trigger a fault code may indicate a defect in the emissions control system or ECM logic. The lack of diagnostic warnings prevents owners from knowing there is a problem until the vehicle fails emissions testing.

My 202 pathfinder started misfiring with sever knocking, Nissan said there is metal saving in my oil which is caused because of the long block engine failure and timing chain loosening. I had my oil changes done every 4K, and I also had the fluids flushed twice in 5 years because of excessive build up. How does this happen.

There's been a loss of power when accelerating, engine has made an odd noise during startup and occasionally a knocking noise when driven longer than a 10 mins. Dealership said there's metal in the oil pan. I saw an article today that said only nissan three and four cylinder vehicles have these issues but my pathfinder has the same problems.

Engine misfiring on left side due to faulty timing chains. Car would not start at times, and engine light flashing. Safety was at risk due to engine being unreliable, misfiring, and we were advised it could possibly stall/cut-out while driving. Problem confirmed by independent service center. Dealer service center would not diagnose without taking engine apart at our expense, they recommended replacing the whole engine, and the car is only 3 years own. There is a know issue with the timing chains on this model of vehicle, yet they did nothing to resolve the problem.

I drove from Pine Bluff, AR to Memphis, TENN in pouring rain. There were many tractor trailers on the highway throwing water back on my vehicle. When I got into Memphis, my vehicle shut down and would not re-start for several hours. I believe this to be a safety issue because if I had driven a little farther and it suddenly shut down in traffic, this would have caused a terrible accident.

Engine pinging/knocking and engine hesitation / surging most obvious in second gear steady throttle around 2k rpm. Doesn't matter what gas is used. Engine hesitation and pinging/knocking is getting worse. NISSAN states its normal operation.

Engine failure while driving. Abnormal engine oil consumption. Oil level dropped without warning and without any warning lights from the vehicle. The vehicle oil level as checked 1 day prior to failure.

WHEN DRIVING OR IDLING YOU GET A SMELL OF ANTIFREEZE INSIDE THE DRIVERS COMPARTMENT. DEALER SAID THE ONLY WAY TO FIX WAS TO GET THE HEATING AND COOLING SYSTEM ON RECIRCULATING AND NOT FRESH AIR. THIS IS CONSTANT PROBLEM NO MATTER THE TWHAT THE TEMP AT URGE ISOUTSIDE.

TL* THE CONTACT OWNS A 2020 NISSAN PATHFINDER. THE CONTACT STATED THAT THE CHECK ENGINE WARNING LIGHT ILLUMINATED INTERMITTENTLY. THE CONTACT TOOK THE VEHICLE TO COURTESY NISSAN (1777 N CENTRAL EXPY, RICHARDSON, TX 75080, (972) 231-2600) AND WAS INFORMED THAT THE OXYGEN SENSOR FAILED AND NEEDED TO BE REPLACED. THE VEHICLE HAD NOT BEEN REPAIRED. THE MANUFACTURER WAS MADE AWARE OF THE FAILURE. THE APPROXIMATE FAILURE MILEAGE WAS 19,700.*DT