Need to replace a knock sensor on my 2005 Ford Explorer Sport XLT 4.6L. Is there a step by step procedure I can use to replace the part tomorrow morning. Also, any pics would be helpful. Is there other items that should be replaced while I have this apart?

The auto has loss of power when climbing hills or towing. On a straight stretch it could get up to 60, Idles great at 1000 RPM. When under load it misses. The codes given were problems w/5,6,7,8 Bank not sure if bank one or two. I have replaced the MAF sensor, all four oxygen sensors on both sides of the Cat. I replaces all plugs and all the coil packs and did a compression test. the cylinders were anywhere from 125lbs to 155lbs done w/a cold engine not hot.

Others thoughts?

Best, Dan

 

You could be right, but I think you are shooting from the hip hoping to hit it !


Before going after a possibly good knock sensor consider connecting a vacuum gauge to the intake manifold and reading the gauge at idle and at approx 2000 RPM. If the reading goes down as the RPM gets higher there is a good possibility you are dealing with a restricted converter. Cyls 5 6 7 8 are on the driver's side and are considered bank 2.

 

Hanky, per your direction. I hooked up a vacuum gauge to the intake manifold and got a reading of approx. 17 lb's at 1000 RPM. At 2,000 RPM it dropped to approx. 5 lb's. When at 2,000 RPM and beyond the gauge was jumping erratically. I heard of another test to pull one of the Oxygen sensors to see if that helped, your thoughts? I also have three Cats on this beast. Wonder who would do the fix for less as I no longer have torches. Gave them to a friend after my racing days.

Dan

 

Yes removing an o2 sensor can help pinpoint which bank.
With 3 cats , you are dealing with 2 pre cats and one main cat converter.
I believe you can separate the main converter from the exh syst. If the readings become more normal, you are looking at a new main converter.


There is another item to look into. Your vehicle probably has a Variable Valve Timing system (VVT). If the solenoid for controlling the camshaft timing for bank 2 is defective, that could be something that you might look into.

 

Hanky, thank you! Sounds like your saying there are two VVT solenoids. I will try to find where they are and if they are testable. I called Midas, they can back pressure test the exhaust to get more of a for sure w/a plugged cat. Your thoughts?

Dan

 

The solenoids are located under the valve covers.
Very important to use the recommended or better motor oil and faithfully have the oil changed regularly.

There are fine screens that motor oil must go through on the VVT solenoids. If allowed to clog performance problems show up.
If you are going to go through the trouble to open the engine to look, you might as well replace the solenoid.

 

Hanky, agree! Whenever I open up an area I typically replace everything that will wear w/time. I will know more on Friday when they check the exhaust for back pressure.

Best,

Dan

 

Hanky/others. I had Midas check the back pressure on the Ford Explorer to find that the Cat on the left bank was plugged as Hanky thought. Nice job Hanky!!! I had them replace all three cats at $1,900 I have always fixed my own work, but no longer have torches/welder since I quit racing. That will change. In any event, the beast runs good again. It can breathe. However, last night I blew my first code after the fix which went something like "Emissions leak or was it a gross emissions leak", in any event it was an emissions leak. What now? There was a small pin hole after the last cat on the drivers side just before the muffler, is that the problem, or something else?

Best, Dan