Toyota techstream and misfire counts

[eljefino]

So a year ago my 02 camry 2.4 4 cyl blew an ignition coil. It had a hiccup transitioning from decel to accel, then finally one day completely conked out, flashing CEL, the whole nine yards.

It's doing it again, the first part, hurky jerky. I plugged in techstream and (cold) idled for a few minutes. Zero misfires on all cylinders. No pending codes.

My techstream is on a desktop computer in my garage and doesn't travel well. THere are resource conflicts with my laptop and the USB dongle.

Does the car "forget" misfires when keyed off? Do I need to go for a 30 mile drive, then pull into my garage and boot up the computer with the car still running? How does the dealer chase down mild misses?

I keep a spare coil in my glovebox. The modern-day ballast resistor, always have a spare.

 

[maverickfhs]

Honestly, I know, you know way better than me and I definitely feel like an idiot by giving you a suggestion.

But in my experience, for some of these old japanese cars, removing the negative terminal for a few mins and then hooking it back can do wonders. Usually code kicks back in either immediately or during the first drive. CEL would come back if there's a misfire detected by the ECU.

Please make sure if radio is an OEM, there's a code for it.

Good Luck.

 

[Kool1]

I would pull the spark plugs and look for any oddities. One plug may look slightly different than the others which will clue you in to the offending cylinder.

 

[clinebarger]

If the misfire doesn't tick the counter enough times.....The misfire count will erase in so many misfire monitor cycles while it's running & will clear the last cycle when the key is turned off.

It usually has to be a constant miss for the misfire history counters to read.

I still scope primary & secondary ignition in situations like this.

 

[KrisZ]

The misfire count may reset, but the code for misfire and which cylinder it happened should be set in the memory, but I think it needs the CEL to be triggered.