2006 Mustang GT Engine Problem

by Brandon Brysch
(San Antonio, Texas)

Question:

I own a 2006 Mustang GT, and at about 1000 rpm the engine bogs down as if it wants to stall out.

I've changed the fuel filter twice and put in 93 octane, Seafoam, fuel treatment etc. The engine light finally came on after I put the Seafoam in (diagnostics showed replace O2 sensor bank 1 and 2, mass air flow sensor, and lean?).

For a car only 4 yrs old and only 40,000 miles would it really be correct to change out the sensors so soon. I feel that it is having fuel problems causing the sensors to react.

Would my judgment be correct or do I need to go spend $300 on new sensors.

Answer:

While It's not usual to have problems this early, it's not impossible. I guess my first question, would be, is the car still on warranty?

If so, I'd get it in to the dealer and have it checked out. If not, here's how to get an idea as to where your issue is.

The oxygen sensor's information only kicks in and is used by the computer when the engine goes from open to closed loop.

(Information from the oxygen sensor + throttle position + mass air flow + throttle position = output, such as increase/decrease fuel, adjust timing etc. Then check O2 sensor again to see what happened and repeat).

What this means, is, that briefly, your car is started with a set of parameters that don't include the O2 sensors.

So if your car is started cold and performs fine, even for a few minutes, then starts to bog, it could be your oxygen sensors.

If it doesn't make any difference, chances are, it's something else.

My best guess would be the Mass Airflow Sensor (MAF). It's not likely dirty, but you could first try a mass airflow sensor cleaner spray and see what happens.

If not, it's best to get it checked out on a scan tool and find out if it's doing what it's supposed to do.

A faulty MAF can cause bogging, stumbling, stalling and poor fuel economy. A bad O2 sensor is more likely to cause poor fuel economy and high emissions, because it forces the computer back into open loop or "limp home mode".

There are a few other possibilities as well, but it's really easy to see which is the culprit on your 06 Mustang using the scan tool.