Fuel related code

Hi,

The oxygen sensor (bank 2 sensor 2) will be on the driver's side. See pics 1 to 3 below.

Now, the idea that it is stuck lean could mean a few things. However, the first thing I would check for is either low fuel pressure or an engine vacuum leak. A leak or low pressure can be the cause of the misfire code as well.

Here is a link that explains how to test the oxygen sensor. If you find fuel pressure is good and there are no leaks, follow this link:

https://www.2carpros.com/articles/how-to-test-an-oxygen-sensor-02-sensor

Let me know if this helps. Also, let me know if there are any strange odors or sounds from the exhaust. One last thing. Is this a 4.6L or 5.4?

Take care,

Joe

See pics below.

Hi,

Here is what to do: First, we need to check for vacuum leaks. If there is one, it could be the cause of the lean fuel mixture.

Here is a link that explains how it's done. Let's do this first before we move on to anything different.

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

Let me know what you find. Your findings will determine what we check next or if there is a need to check anything else.

Let me know. Hang in there. We'll get through this. I'm here is you have questions.

Take care,

Joe

Hi,

As far as the fuel pressure, I attached the manufacturer's specs below. Note I highlighted a 4.6L V8. If you have the 5.4L, the pressure is the same.

Here is a link that explains in general how to check the pressure:

https://www.2carpros.com/articles/how-to-check-fuel-system-pressure-and-regulator

If possible, place the phone near the exhaust so I can clearly hear what it's doing when you hit the throttle. I tried listening several times, but the sound quality on a computer limits what I hear. Hopefully, placing the recorder closer to the exhaust will help.

I also noticed the engine has some slight backfires when the throttle was released. Are there exhaust leaks? If so, are they before the catalytic converters?

Let me know what you find.

Take care,

Joe

See pic below.

Hi,

The pressure is perfect. Also, the FRPS voltage seems fine as well.

I dug around a little with regards to the P0193. See pic 1 below. If you look at pics 2 and 3, they provide the location of the FRPS.

In pic 1, the manual indicates to use pinpoint test DD. I attached that diagnostic list for you as well. However, it is very extensive. Take a look at it and let me know if this is something you feel comfortable doing.

Before attempting the diagnostics, make sure the connector at the sensor is in good condition, free of damage and corrosion.

Let me know,

Joe

See pics below.

Hi,

The idle air control valve (IAC) is responsible for maintaining the idle speed. However, based on what you experience, it could be an engine vacuum leak as well.

If you look below, I attached a pic of the IAC. Make sure the connection is good and make sure the throttle plate fully closes. If everything looks good, try servicing the IAC. Here is a link explaining how it's done:

https://www.2carpros.com/articles/idle-air-control-valve-service

Before jumping right into the IAC, confirm there are no vacuum leaks. If nothing is found, then go to the IAC.

Let me know what you find or if you have other questions.

Take care,

Joe

See pic below.

Hi,

It sounds like a misfire. Have you gotten any misfire codes?

Joe

Hi,

When you hit full throttle, a lot of air and fuel get into the cylinders. So, it could misfire if the plugs are worn or there is another issue with the ignition system. When was the last time it was tuned up? Also, have you pulled plugs to inspect their conditions?

Joe

Hi,

Wow! If they have 177,000 miles on them, you got your money's worth from them.

Let me know. I'm interested in knowing what you find. Also, when you pull the coil off the plug, check to see if there is any oil down inside the tube or on the boot.

Take care,

Joe