P1923 sooo drove car home 2400 miles, back in NH now. Car drove about 2000 miles fine and then started misfiring around New York, blinking check engine light all that good stuff. Got home replaced all coil packs and pcv. Car still misfired blinking CEL under hard throttle. Bought icarsoft vaws v3.0 because liquid damaged my laptop before leaving. From scanning I see…
I/M monitors
Completed - 2
Not Completed - 5
Misfire - n/a
Fuel - ok
Component monitor - ok
Catalyst - INC
Heated catalyst - n/a
Evap - INC
Secondary air - INC
Oxygen sensor - n/a
O2 heater - n/a
Current codes:
P1923 - implausible signal check DTC memory of engine control module 2 (current ecm software version is 10)
P1653 - implausible signal read DTC memory of abs control module ( no abs light)
00191 - front passenger exterior door handle touch sensor (open circuit)
00924 - defective relay for headlamp washer system (fuse is pulled and everything to washer bottle removed)
02261 - implausible signal data medium
01134 - electrical fault in circuit alarm horn ( horn works)
With this scanner I was actually able to run adaptation through the engine modules and everything seems fine as far as I can tell, throttle bodies, injector circuits , Cam sensors, 02 sensors, relays. Interestingly enough my symptoms started exactly like this bulletin.
I am going to check couple more things and find someone who can clear the memory faults before attempting dealer fraud service. Also I interesting bank 2 runs kinda lumpy, doesn’t stall and seems to drive rather fine until misfires occured, but when idling you can feel “something”… Off. Starting to think I fouled an O2 sensor on the driver’s bank, now I am thinking it is literally an ecm “ghost fault” that was caused by having no intake flaps, or from the battery dieing, or a catalytic converter is bad on the driver’s bank. I did blow the clutch brake switch fuse at one point and took it for a ride like that and it drove perfect in some kind of closed loop settings I’m assuming which makes me think there is actually no mechanical or sensor failures.
Sincerely Johnny 5, I need fucking input.
Update: sooo immediately after posting this I say to myself “oh ya I want to check the gas cap thoroughly before I go to bed”, sure enough the purge valve inside the cap doesn’t allow air to pass through into the gas tank which kinda makes sense with the issues I’m having, so I ordered it. Normal shipping from fcp euro from CT to NH is next day. So glad to be home.
For anyone asking themselves how this results in random misfires and bank 2 running weird, it has to do with tank vacuum, fuel pressure and fuel rail length + bends. One easy way to tell if it is fuel cap related is, when your tank is under a quarter the problems will become worse as mine did, which explains why it didn’t start until New York. Until then I was refilling tank above a quarter, in new York I was going to try and sleep so I was trying to get as close to home as I could before napping. As the tank gets empty and air isn’t introduced to the fuel tank to equalize pressure the pump will have a harder time sucking as vacuum becomes resistance. Also once it passes the fuel regulation block it has to travel farther and UP against gravity over the intake manifold as bank one doesn’t. This would also explain the IM monitors not completing as evap and such do checks on key cycle. This also explains why the epc light would very intermittently show when fuel level got closer to empty. Also explains why I absolutely had to rip on it to redline after changing coil packs and plugs to get it to give me blinking CEL the other day, tank was a little over half full. It would be very beneficial to consumers for manufacturers to put some kind of sensor on the cap valve, but as electrical circuits going into the gas nozzle area would be a fire hazard, I understand why they don’t.