How can clear the codes for rngine light being on

Are you asking how to clear the check engine light?
Buy a cheap code reader ( $20 ) plug it in the OBD2 port which has to be no more than 3 feet from the steering column and clear the code(s).
If the check engine light comes right back on after you have cleared the code(s),read the code(s) and correct the problem(s).

please scan the ECM for codes and post them

Po172 refers to an oxygen sensor. But after you service the part you need to clear the code with an OBD II scanner. You can get a reliable inexpensive one at Harbor Freight. After you clear the code then you to start the car and drive it to see if the code comes back on. Also if you have a vacuum leak this can cause the system to run either rich or lean depending on circumstances.

Could be temp. sensor.you need new one.

you can disconnect the battery (both terminals) leave disconnected for 10 to 15 min, that should reset the light.

Only the computer can clear history codes . If the problem was fixed in about 100 ignition cycles the computer will clear this codes . Code reader . will it check Codes in the EBCM - electronic brake control module ? ABS DTC'S

clear light and see if light comes back on. turn key from on to off 40 times to clear light and codes

You will have to take it to a repair shop that has an OBD I scan tool to clear the code(s), you maybe able to clear the code(s) by disconnecting the battery for about 10 - 15 min. And see if that works (depending on what type of fault code was stored to set the light). Hope this helps.

The codes all have to be cleared by using a scanner but if the reason the light was on has not been fixed the light will just come back on. If the problem has been fixed the light will go out on it's own after 25 warmup/cooldown cycles. Autozone will read the codes for you free of charge but they will not clear the codes to shut the light off. You either need to buy a scanner or take it to someone who has one. Good luck

make sure your not getting oil down into the holes where plugs go this can mess with the wires.Is it actually skipping?