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View Full Version : Fyi: Check Engine Light


Super White Alero
07-15-2005, 01:04 AM
Ok, I just completed my course in the new ASE certification for Missouri Clean Air Act. I thought this info would help most of you post 1996+ cars. As of 1996 the federal mandated all cars to be equipped with the OBD II sensor that monitors the;
cat
evaporation unit sensor
EGR sensor
malfunction light off
malfunction light on
ABS sensor
airbag sensor.....
etc, etc, etc......

Well you already knew this, but Missouri is tryingto push a law into affect that forbids the erasing of all check engine codes. Good and bad things about engine codes

First the good:
1. Allows you to daigonis and troubleshoot the problem(s)
2. Keeps track of all the problem(s) you vehicle experienced for 40 drive cycle(note a drive cycle is starting the car and allowing it to have a temperature change of 60 degrees and must include speeds up to 65 mph)
3. If the sensor and parts are not communicating properly the manufacture may/can be held liable to replace the sensor*
4. It takes 3 drive cycle to remove the check engine light

The bad news
1. If you erase the code and the sensor is bad, the ECU now thinks that the sensor is new and therefore will throw a new code of what it believes the problem is.
2. If you get into an accident and you do hit the governor speed limiter in the last 40 drive cycle that info is recorded.
3. the light is annoying
4. it takes 3 drive cycle before the light is removed.

Its your call, in California its illegal to erase the codes and any smog certified tehnician caught will have they're certification revoked and fine up to $5000. Lucky Missouri still haven't pass that law yet.

bigd6983
07-15-2005, 08:34 PM
what the heck, i have a code reader that i bought in a hardware store, it displays the codes and then erases them........i dont think it would be illegal if they sold it in a public store,i live in cali, never heard of anything like that.........do you have an article?

gre0481
07-18-2005, 09:14 PM
alright,

Hear I am at 51256 with my 2.2 ecotec, just after running a wild goose chase that took me an extra 36 miles to get to work.

I've changed my Oil every 3000, on the nose (sometimes a few hundred before, sometimes after) Replaced my air filter twice. Change my oril filter every time (bought the dang shallow socket for it) ANd now a check engine light?

What could it possibly be? ANy common problems?

Do I need to pay an arm and a leg to have a dealer read my chip?>
For a simple fix most likely?

gre0481
07-18-2005, 10:23 PM
Ok, the book says a constant service engine soon light is emissions, and flashing is running related, ie misfiring, rough idle, stalls.

first thing for emissions it says to check your gas cap and make sure its on, duh :P

Then it says bad fuel. In recent times, who knows what quality fuel is available, and who has it. Lucky to have it at all right?

Had the same problem in a 99 sohc 2.2l escort, poor gas on camp pendleton, once I had a tank or 2 in her on the way home from mich, it never came on again.

Going back in time, Dad had a 94 Pontiac Transport 3800,
The egr sensor went out after 68,000. Why should a vehicle with a 100000 mile warranty or whatever, supposably everything maintenance free aside from oil/oil filter, air filter, basic maintenance, Need an EGR?

To be on the safe side, I'll sneak my car into the shop tomorrow and have a mech run a diagnostic. (boss is a pennypinching money grubber)
It could be dead as all hell, and he won't even allow you to bring in your car to change your pads. Not that it's against the rules or anything, we can work on our own vehicles for free. Bah

I'll post the results

Super White Alero
07-18-2005, 10:27 PM
Originally posted by bigd6983@Jul 15 2005, 07:34 PM
what the heck, i have a code reader that i bought in a hardware store, it displays the codes and then erases them........i dont think it would be illegal if they sold it in a public store,i live in cali, never heard of anything like that.........do you have an article?
Quoted post



A code reader??? WTF is a code reader???

You mean a scanner, cause they are the only thing that can erase codes, and those things cost anywhere between 900-4000 usd. I got a Snap-On Graphical Diagonsis scanner. And in California any Ceritifed Smog Inspector caught erasing codes will be fined and their cerifiecation removed.

You don't erase SES or Check Engine lights, they go off automatically after the problem is corrected. The ECU relearns itself after 3 cold start ups.