jyeung528

While driving to Vegas this weekend, my CEL started blinking as I was going uphill.

it would blink and go away, and blink and go away while driving uphill.

when there was no incline, it would not blink anymore, and then come back when I reached another incline.

by the time I got to Vegas, it was not blinking and there was no code to pull when i used an obdII scanner from autozone.

my guess is dirty injectors? I am using oem plugs that were changed about 30K miles ago.

anybody have this experience and figure out what it was?

dparm

Find a place you can drive uphill again. If it comes back, I'd be willing to bet it's something oil-related.

jyeung528

there were uphills coming back from vegas and it never came back on my drive home.

I can't imagine that it is oil-related as there is an oil light for oil pressure/oil pump issues.

My guess is a misfiring, but I'd like to know why...

Slows2k

It was misfiring, and the scanner at Autozone isn't smart enough to pull the data or you are running with the back-up fuse missing.

dparm

Flashing CEL doesn't mean misfire...it means "big big problem". Very unusual that the light didn't stay on.

Slows2k

No, it means the engine was misfiring bad enough to damage a catalytic converter.

Temporary misfire DTC's can clear after the misfire is no longer present depending on how long the engine has been run without a misfire.

More likely the cheap scanner doesn't have the ability to retrieve temporary DTC's

jyeung528

based on what you are saying, it sounds like i had temporary misfire dtc's that did indeed clear.

the blinking CEL did go away and stayed away. it came on during uphills, but never came back again, even going uphill on the way home.

i don't know if the scanner was cheap or not, but it said there were no codes, which did not seem unusual since there was no cel light blinking or otherwise on.

so it was a misfire.

how can i possibly diagnose the problem without the codes?

it was definitely related to driving uphill.

spark plugs are oem with 30K miles, so i assume they are fine.

perhaps it is the injectors? should i throw in a bottle of techron? I have a total of 110K miles on the car/injectors.

SpitfireS

What fuel do (did) you use during that trip?
Any change in that?
Going uphill changes the engine rpm / throttle position ratio.
Maybe there was a slight knock & ignition retard = misfire due to bad fuel?
Just guessing here.

Did you see blue smoke coming out of the exhaust going uphill?

How steep was that uphill drive?

jyeung528

I filled up at a 76 in barstow. no change in octane or anything.

i did not notice any smoke coming out, but i did not look either. i was mesmerized by the blinking CEL that stopped and blinked again and stopped and blinked again, etc.

since it has gone away, i will just say i filled up with a bad tank of gas.

thanks for the help.

s2kobsession

This is straight out of the movie "cars" isn't it?

no clue about your problem though. I would wait until it flashes again and then hook up the reader ASAP to pull the code b4 it disappears