2003 S-10 "check engine" light

[57 3100]

guys,
my 2003 s-10 extreme 4.6 v-6 with 65k miles.
when i get on the highway and am going 65-75mph my "check engine soon" code will flash on and off fast for about 20 flashes, then stop for about 30 seconds, the start the flashing again.
it will do this for 10 minutes or so, then stop.....
do you got any ideas what is going on ?
cant use my scanner because it wont stay on...
the truck is running perfect.

[68C15]

flashing light means you have a catalyst damaging missfire. the codes will remain for 40-50 ignition cycles without failure.
just thinking here; you have a wet enviorment now, right? is there moisture in the cap?

[57 3100]

Originally Posted by 68C15

flashing light means you have a catalyst damaging missfire. the codes will remain for 40-50 ignition cycles without failure.
just thinking here; you have a wet enviorment now, right? is there moisture in the cap?

thanks for the info.... what is a "catalyst damaging missfire" ?
about 8-10 months ago i had a complete tune up and #5 injector replaced.
i didnt know the code would be stored for, so when i get a chance i will scan it and see what it says.
is the "catalyst damaging missfire" something serious ?
like i said, the truck is running perfect with no rough idle or while at speed.
thanks a bunch

oh yea, no possibility of any moisture in the cap..

leonard

[68C15]

Originally Posted by 57 3100

is the "catalyst damaging missfire" something serious ?

about $600 serious. that's the going rate for a GM catalytic converter. aftermarket ones only last about 6 or 9 months.

I'll be watching for your codes.

[57 3100]

Originally Posted by 68C15

about $600 serious. that's the going rate for a GM catalytic converter. aftermarket ones only last about 6 or 9 months.

I'll be watching for your codes.

oh, a catalytic converter... no kidding ? wow, not cheap.
i will check the codes tomorrow when i get off work and will post.
how will the truck run if i take the cat converter out and not use one ?
will it screw with the computer ?
thanks again..

leonard

[57 3100]

also,
does the blinking "service engine soon" light mean i am still experiencing an engine misfire ?
like i said, 8-10 months ago it was running really rough when i brought it to my mechanic and he did the tune up and #5 injector. now it runs very smooth.
or did the misfire from back then ruin the catalytic converter ?

leonard

[gchemist]

Post the codes. The codes are a starting point. If the cat is toast, you'll hear rattling.

[68C15]

Originally Posted by gchemist

If the cat is toast, you'll hear rattling.

if it is damaged to the point of not doing it's job you will get a P0420 or P0430 (converter efficiency low, bank 1 or 2 respectively)

if removed you will have high cylinder temps and pressure burning pistons along with codes for insufficient EGR flow and poor driveability

[57 3100]

ok guys,
i just did a scan, and it says there are no codes.
i am using a hand held actron pocketscan i bought 6 months ago from autozone. in the past when the engine light would come on and stay on, i would get codes that were for evap, i think.....cant remember, but i erased them at that time.
here is all i get now with the scanner hooked up and key on:

0 codes
mil off
monitrs
o inc
7 ready
misfire
fuel
comp
catlyst
evap
02 sensr
02 htr

and i get the same results when the engine is started.
my instructions are kind of vague. what is mil off and mil on ?
i only get mil off, and cant make it say mil on.

so, i still wonder why my service engine soon light flashes the way it does when im on the highway ? and im reading no codes ?

thanks for the help guys.... any suggestions ? should i just keep driving it since it is running fine ?

leonard

[68C15]

it sounds like your scan tool, or rather a code reader, is only able to acquire generic codes, not manufacturer specific. gen. are P0xxx while man. spec. are P1xxx, P2xxx etc.

mil on means PCM is requesting the light on.

I understand the data you show, nothing out of the ordinary.

you might end up taking it to a shop. my first move as a pro tech would be to hook up my enhanced scan tool and look at fuel trims and missfire data followed by a test drive.

[57 3100]

Originally Posted by 68C15

it sounds like your scan tool, or rather a code reader, is only able to acquire generic codes, not manufacturer specific. gen. are P0xxx while man. spec. are P1xxx, P2xxx etc.

mil on means PCM is requesting the light on.

I understand the data you show, nothing out of the ordinary.

you might end up taking it to a shop. my first move as a pro tech would be to hook up my enhanced scan tool and look at fuel trims and missfire data followed by a test drive.

thanks for the help..... much appreciated....
in the past, when i had a code to read, it did start with POXXXX if i remember correctly.

so, when my reader says "mil off", is that ok ? if not, what do i have to do ?

i guess the next day i ahve off i will have to take it to my mechanic.

thanks again..
leonard

[CC69Rat]

57 3100 -- Do you run Ethanol gas in it?

[57 3100]

Originally Posted by CC69Rat

57 3100 -- Do you run Ethanol gas in it?

nope, just regular gasoline...
havent had it up to 70mph for long, but i put my airrade air cleaner system back on, and so far so good... maybe the factory air cleaner was too restricting ?

[CC69Rat]

I was thinking a rich condition, so yes .. maybe adding more air will lean it out to the point the CEL will cooperate? Is the the CEL or the SES light?

[57 3100]

thanks... it was the CEL