MAF issue & clearing codes

[ephect]

i have a small issue, i know my MAF is possibly screwed, as a test i can unplug the sensor and the car continues to run without a hitch. it should cough and splutter as it doesnt know how much air its getting. So on that basis it makes sense that my car is running on a base map. I have a new MAF which will be going in tonight.

i have done a code check to see if its logged anything, nothing but 12's all round.

I've heard that reseting the ecu (DC battery or ecu fuse) only clears the temporary codes and wont clear/reset any hard codes set, is this true? if so is there a way to clear/reset the ecu without seeing a mechanic or holden for a tech1/tech2 hook up?

[delcowizzid]

just dissconnect the battery for the time you are doing the job should be enough to clear the errors.it will run with no maf it has backup tables to run without it

[ephect]

done and done. as a test, i started her and then D/C'd the MAF, and the engine light come on straight away, BOOYYAAHH!

D/C'd the battery again checked codes all clear, will see how she goes over the next week.

as a matter of interest, is there any such thing as hard codes that need to be reset by tech?

[cander24]

as a matter of interest, is there any such thing as hard codes that need to be reset by tech?

In a word, no.

[vr1uz-fe]

ahh the o2 secor has more to do with the air flow

the maf is just a fine tunning thing for the computer

if you have codes they arnt just there too look pretty they will come back

when i clear codes on the scanner i go for a drive they usally come back this is how i diognosie the prob

[vr1uz-fe]

oh yea the dash codes arnt the same as proper falut codes on the scanner and the scanner has codes that many on here have never herd of

[vr1uz-fe]

btw a scan tool will go for about $7000 these days

[ephect]

yea i dont think i'll be getting a scanner any time soon lol

the O2s are around 6months old, and i know my mixtures are fine my air/fuel meter keeps me informed. i've known about the maf for a while but didint have the cash, and the fine tune side is what im after.

[wamboin23]

ahh the o2 secor has more to do with the air flow

the maf is just a fine tunning thing for the computer

if you have codes they arnt just there too look pretty they will come back

when i clear codes on the scanner i go for a drive they usally come back this is how i diognosie the prob

yeah o2 sensors have heaps to do with airflow??

MAF reads the amount of air coming into the engine, o2 sensor detects the amount of fuel/oxygen in the exhaust gas. o2 sensor is only fine tuning, no more than 10-15%.

If a MAF was only fine tuning, why do vehicles need a MAFless tune when the MAF is removed?

and if the issue is fixed, most of the time engine DTC's won't come back once the battery is disconnected/key is cycled 20 times.