P0101 Code - Still Searching For A Solution...

BretD04GMC · June 3, 2010

Thought I would post this to share information.

Like many others, I periodically get an SES light and P0101 code (MAF signal problem) on my truck. It will go for long stretches just fine , then one day trigger the SES and set the code. After the typical (3) ignition cycles, the SES light will turn off. There's never been any drivability issues.

Many of us have heard the myth of "it's because of a K&N filter". Well, I've triggered the code with a K&N filter, an AEM DryFlow (no oil filter) and even tried reinstalling the factory air box and filter. In all 3 cases, at some point the SES went off and set a P0101.

Just the other day I replaced a few parts to see if it would finally resolve this issue. I switched to a Volant Powercore filter, including the pre-filter, dropped in a Granatelli MAF with cold air tuning, and even replaced the MAP sensor (GM suggests this).

Today, on my morning commute, the SES went off again and set the P0101 code.

The only common denominator among all my experimenting is the K&N Series 77 aluminum intake tube. Not sure what, if any, affect it may be having.

It's more of a nuisance than anything else. I'd just like to find the gremlin once and for all.

rmck490 · June 4, 2010

Try reading this.

It could be something besides airflow. Maybe the MAP sensor or electrical?

Willshire · June 4, 2010

Vacuum leak to the map sensor. Use a piece of vacuum hose from your ear to the vacuum line of the map. Follow the entire line . You will hear a slight hissing if a leak is detected. Check the voltage to the Maf as well. My maf reads 5g/s at idle and over 210 at wot.

Stevens03 · June 4, 2010

I've read so many issues with aftermarket MAF sensors... I'd go back to stock to avoid some. Then look for vacuum leaks.. flex the lines a little too while idling so you can get a good look.

nickvrebel · June 4, 2010

I was going to say get some MAF cleaner (yes, there is a special cleaner) but if you swapped sensors this should eliminate that.

you either have an electrical issue or an air leak somewhere.

BretD04GMC · June 4, 2010

Try reading this.

It could be something besides airflow. Maybe the MAP sensor or electrical?

GM recommends first replacing the MAP sensor when a P0101 code is getting set. I just put a new MAP sensor in when I swapped the MAF and air filter.

I readjusted the air tube connections last night as well as disconnected the negative battery cable to reset the computer. We'll see what happens. If the code shows up again, I'll double-check for air leaks.