Fixed and cleared codes P0174,P0401,and P0406 but........

So I left my car with a mechanic to check the codes and why they are appearing. He said that there was a air/gas leak on the some type hose(vacuum) that was essentially completely broken, he replaced it. The egr came back good. He later cleared the codes, after fixing the problem that he saw, but after driving the car for 30 mins the check engine light reappeared again. I searched up why and I read that the check engine light might/ will still appear/reappear but after driving the car 60-100 miles and doing many drive cycles letting the car run some tests, the light should turn off. But is that really true tho? Even when starting to do the drive cycle, the check engine light isn't supposed to come back on at all? Is there a difference between clearing a code and erasing a code? Do I need to do a drive cycle everytime someone clears and/or erase a code?

Is this normal? and Could it be that there others issues that needs fixing? I haven't scanned the car yet because I just found out because I was driving my car? I'll probably do another post explaining why or if everything is fine

First step is scan the vehicle and then go from there.

An ODBII Drive cycle is intended to bring system monitors online. Example being you disconnect the battery to change it. After reconnecting you may not have any codes, but scanning the system will reveal a number of systems that are not online yet. Doing a drive cycle will generally bring all of these systems online unless there are other issues preventing them from doing so.

Scan the vehicle first and see what it is telling you.

The EGR may be functioning fine. But if he didn't clean out the throttle body passage that the EGR attaches to, you will still have the low airflow rate that was triggering your P0401 code and the check engine light. Did he say he pulled the EGR valve off and cleaned out the throttle body passage?
You can stop by any autoparts store and they'll read the codes for you. On a vehicle that old you may just want to buy your own code reader and learn how to use it. They're simple to use.


Ancel OBDII Scanner on Amazon


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If you're still getting P0174, a scan will probably show +25% or more for Long Term Fuel Trim - Bank 2. This can happen even if the problem causing the lean DTC has been fixed because the adaptive fuel strategy requires time to adjust to the new conditions. But, if the problem has indeed been corrected, the scanner will also show LTFT2 dropping after every trip until it eventually settles in the normal range.