New 2001 Quest GLE owner here.
Just registered it and this happened:
Symptom: Recently developed misfire. Rough misfire sounding engine. loss of power, sometimes stalls at idle unless in neutral/park. Car is pretty much drivable to get it to garage and still has pretty strong accelleration despite misfire. 240K miles.
Troubleshooting:
Found no change at all in engine sound (misfire sound) when plug wire for cylinder 5 is pulled (Draws nice spark at cap). All other disconnected plug wires cause noticable (extra) misfire. CYLINDER 5 MISFIRE(?)
Removed #5 plug. Seemingly good spark there. Plugs look a little rich. Swapped plug and wire from another cylinder, no change in symptoms. GOOD SPARK(?)
Stethoscope on fuel injectors show noticable weak or no sound on cylinder 5 injector when compared to rest. (That would explain symptom!) Replaced injector but symptoms (Unplugging #5 spark wire and no change in misfire) not even improved BUT there IS noticeable change in idle when #5 injector unplugged while idling. (What does THAT mean?) GOOD FUEL(?)
Compression test on #5 cylinder is 160. GOOD COMPRESSION(?)
Sparks from coil tower center (with distributor cap removed and cranking engine) seem normal as seen in a youtube video. no unwanted sparks near base of tower/distributor to ground as seen as a common trouble in several youtube videos that demonstrate this common problem (Checked this because cylinder 5 wire is right next to the tower):
YouTube
(trouble demonstrated at 4:27 minutes into video)
Are there other distributor problems that could cause this misfire? (Is it a misfire?)
Recent history:
Ran great even after I bought it from previous owner after their accident (No misfire, car parked for just a few weeks); and driver-side front end damage repaired: Transmission oil cooler line ruptured, Bent metal (cross-piece in front of radiator), Bent radiator (Formed back to flat shape), replaced headlight & indicator plastics, Cooling fan smashed & replaced. Battery pushed into air box deforming it (Repaired with duct tape to seal it), Relay box plastics smashed but relays and wiring intact.
Timing has not been checked.
Codes:
P0325 Knock sensor B1 Problem
P0300 Random Cylinder Misfire Detected
P0420 Catalyst Efficiency Low
P1605 A/T Diagnostic Communication Line wrong signal
P0745 Line pressure Solenoid Circuit Fault
P0134 Low O2S Activity B1S1
P0105 Absolute Pressure Circuit Problem
Codes Cleared and these came back:
P0325 Knock sensor B1 Problem
P0745 Line pressure Solenoid Circuit Fault
I'm unsure of what to do next and so are 2 of my mechanic friends.
Would a plugged catalytic converter cause this? It might have took a hit in accident but this problem developed quickly.
Distributor?
Timing belt?
MAF?
Wiring harness in front of radiator damaged?
I'd like to troubleshoot before buying more parts if possible.