MAF sensor

Hi Tyler,

This is going to vary based on what the RPM is at when you are looking at it. The MAF sensor simply measures the mass (amount) of air coming into the engine so that the PCM can add the correct amount of fuel.

A rule of thumb on a MAF's air flow rate at 500 rpm is 1 gram per second per liter of engine displacement. It looks like this reading is 9.07 g/s so was your RPM about 833 or idle?

Here is a good video that shows how to test a MAF with just a meter. Then a guide that shows how to clean one if needed.

https://youtu.be/p0ocaDmcAIM

https://www.2carpros.com/articles/mass-air-flow-service

Okay. Here is a guide that takes you through the basics of checking for lean codes. It is not just the MAF but that is one possible cause.

https://www.2carpros.com/articles/repair-lean-mixture-codes-p0171-or-p0174-on-some-manufacturers

Also, here are the possible causes for the P0171.

Let me know what you are finding with these systems and I can help with understanding what is happening if you would like.

Okay. Both banks that are lean and being commanded to go rich but not doing it means that the system just can't do it. This is normally a fuel pump issue or an air leak past the MAF sensor. If you look at both of your short term fuel trim and long term bank 1 and 2 it is showing around 29 for long, and 10 for short term.

This means that you don't have enough fuel in the exhaust and so the o2 sensor is telling the PCM to add more fuel. The fact that the long term is so positive as well means it has been doing this for a little while and it just can't compensate.

Short term should be bouncing around 0 but going positive then a little negative. Long term should not be more than +/- 5.

The fact that both are positive means that your issue is something that effects both banks. Fuel or air coming in past the MAF because the MAF is not seeing any large amount of air. It is reading just about where it should be.

These two guides will walk you through how to diag this. Click on the links below and read through what is needed. Let me know if you have questions about it.

https://www.2carpros.com/articles/how-to-use-an-engine-vacuum-gauge

https://www.2carpros.com/articles/repair-lean-mixture-codes-p0171-or-p0174-on-some-manufacturers

Seafoam will not make an engine run lean, however if you are concerned about it just fill the tank and it will dilute it. Seafoam is used to stabilize fuel and clean injectors and other parts. It doesn't effect any of the sensors because it is basically just a high octane fuel.

Unfortunately, I can't tell but that is a rubber vacuum line. When the engine is running, if you spray it with carb cleaner and the RPM raises then it is possibly your issue. Refer to step 4 in the link below.

Either way, it needs to be repaired. I would remove the hose and take it to a parts store. They sell this type of hose in bulk, so they can match the length.

You will need to replace this and then retest.

https://www.2carpros.com/articles/how-to-use-an-engine-vacuum-gauge