1996 chevy truck 5.7L has codes P0172, P0172 were

P0172 LEXUS - System Too Rich Bank 1
Possible causes
Faulty front heated oxygen sensor
Ignition misfiring
Faulty fuel injectors
Exhaust gas leaks
Incorrect fuel pressure
Faulty Mass Air Flow (MAF) sensor
https://www.autocodes.com/p0172_lexus.html

erase code again , then disconnect battery for a few minutes, reconnect, see if code comes back. hopefully this resets computer. you don\'t have a reset button on steering wheel do you ? replace your fuel filter, if you haven\'t lately. maybe that will help.

what has to be done about a p2188 on a chevy aveo, could it be the gas?

To many things that can cause the check engine light to come on. It could be as simple as a bad gas cap to a miss fire in your ignition system.
If there is an Auto Zone around your area, they scan for the DTC codes free of charge and when the issue has been addressed. The check engine light will reset if self after 3 consecutive start cycle if there is no oter issues.
Thank you for using fixya and good luck

it could be something simple or something complcated but you can have the check engine light diagnosed for free at auto -zone they will be able to tell you what that code is i dont recall that code at the time.

Just disconnect the battery (negative terminal) and turn the headlight switch on for about 15 minutes. This should reset the PCM. Otherwise go to Advance and have them hookup the code reader and reset the codes. Thanks

You can purchase a code reader for around $50 on ebay. This will allow you to read the computer code and look that up to see why the check engine light is on. Auto Zone, AAMCO, and other places will read the codes for you for free. I would start there.

Prior to that, check your gas cap to ensure that Habib tightened it properly. That will throw a code. If it was loose, tighten it and the light may go out by itself.

Try a new gas cap first. I say this due to the fact that the light is intremitant, and the fact that the computer checks for vacum to the the tank periodicaly. The gasket on the cap may be just at the stage were it seals most of the time, but not all of the time, depending on temp and how tight you put it back on. With out codes of course this is just a **** shoot. You can always buy a DIY code reader for up to a couple hundred bucks.

YOU NEED TO HAVE SOMEONE READ THE CODES. SOME PARTS HOUSES (ADVANCE AUTO AND AUTO ZONE) WILL DO THIS FREE OF CHARGE. ONCE THEY TELL YOU WHAT THE CODES ARE YOU WILL HAVE TO FIX THAT PROBLEM BEFORE THE LIGHT STAYS OUT. YOU CAN RESET IT BY DISCONNECTING THE BATTERY FOR A COUPLE MINUTES, BUT THE LIGHT WILL KEEP COMING BACK ON UNTIL THE VECHILE IS REPAIRED

you need to go to an electronic specialist or you can buy one of the scanners that clears the codes for you from advanced auto or autozone or some place like that.