Ok so I had the same problem and like others mentioned RRM is in SoCal so the programing maps for the piggyback are set for that area. But your car's computer uses 2 different fuel maps from the factory. It has its base programing which is only going to function properly with stock components but fortunately is only used BEFORE the O2 sensor is at operating temps. O2 sensors don't even function until 600 degrees F. Now keep in mind this very important fact; This is an O2 sensor not a C8H18 sensor. Meaning it doesn't read fuel, it reads oxygen. If you aren't burning the fuel then your O2 is going to be high and your computer will read that as lean (p0171) when there isn't anything wrong with the AFR you just aren't burning the fuel. This also explains why some people (myself included) also get a "random multiple misfire" code.

The solution that I've found for my car was to regap the spark plugs. NOT TO THE FACTORY SETTING. The factor setting for the 4G69 spark plug gap is .028"-.031". This is not a hot enough spark to burn all of the fuel/air you've got. You've actually lowered the resistance of the combustion chamber and you don't get a hot enough spark.

Regap your spark plugs to the 2.0L settings of .039"-.043" (1mm-1.1mm) This will provide a hotter spark and more complete combustion. And more importantly, if you live somewhere with OBD-II vehicle inspections, no check engine light.

But it is very important to make sure you don't have any leaks in the intake system, and that the MAF is clean just in case. DO NOT USE BRAKE CLEANER TO CLEAN YOUR MAF! Use an actual MAF sensor cleaner available at Kragens/Advance/AutoZone/O'Reilleys whatever you've got in your area.

As you regap your plugs unplug the battery and reset your leaner fuel trim. Then just drive around for a bit keeping it under 3k RPM for about a half hour city drive and you should be fine.

Let me know!

 

**WARNING: SOME SCIENCE CONTENT**

Ok so I had the same problem and like others mentioned RRM is in SoCal so the programing maps for the piggyback are set for that area. But your car's computer uses 2 different fuel maps from the factory. It has its base programing which is only going to function properly with stock components but fortunately is only used BEFORE the O2 sensor is at operating temps. O2 sensors don't even function until 600 degrees F. Now keep in mind this very important fact; This is an O2 sensor not a C8H18 sensor. Meaning it doesn't read fuel, it reads oxygen. If you aren't burning the fuel then your O2 is going to be high and your computer will read that as lean (p0171) when there isn't anything wrong with the AFR you just aren't burning the fuel. This also explains why some people (myself included) also get a "random multiple misfire" code.

The solution that I've found for my car was to regap the spark plugs. NOT TO THE FACTORY SETTING. The factor setting for the 4G69 spark plug gap is .028"-.031". This is not a hot enough spark to burn all of the fuel/air you've got. You've actually lowered the resistance of the combustion chamber and you don't get a hot enough spark.

Regap your spark plugs to the 2.0L settings of .039"-.043" (1mm-1.1mm) This will provide a hotter spark and more complete combustion. And more importantly, if you live somewhere with OBD-II vehicle inspections, no check engine light.

But it is very important to make sure you don't have any leaks in the intake system, and that the MAF is clean just in case. DO NOT USE BRAKE CLEANER TO CLEAN YOUR MAF! Use an actual MAF sensor cleaner available at Kragens/Advance/AutoZone/O'Reilleys whatever you've got in your area.

As you regap your plugs unplug the battery and reset your leaner fuel trim. Then just drive around for a bit keeping it under 3k RPM for about a half hour city drive and you should be fine.

Let me know!