and they don't throw any codes, what exactly does the engine do. I mean is there a significant amount of lost power? Does the computer actually cut out every other cylinder? or something like that. My '02 4.6L Screw is such a dog, but it just feels like something is holding it back. It doesn't even break the tires loose on take off, and I cant help but say I was completely embarassed the other night when headed home, some guy in a Ford Focus smoked my **** from the light. I mean after a while, i caught up to him, but he left me by about 3 or 4 cars from the light. That, I thought, was completely unacceptable. I have an XCal II on the way, but my god, does it take a 500 dollar tuner to be able to beat a 4 cylinder off the line? I don't mind modifying my truck at all, Its just that this is my first Ford, and I am not quite convinced about the Ford Product right now. My truck runs really smooth, idles smooth, and accelerates smooth, never stumbles or idles rough, it just doesn't feel like it has much power. Any technical advice would be great. I am going to change the plugs, upper O2's and switch to 5W-30 oil this week to help with the infamous "lifter/cam follower tick" and double check and make sure the tick isn't an exhaust leak again. And If the O2's were bad and not throwing codes, what would be symptoms or sure signs of bad O2's? Also, would clogged cats cause such a deficiency in power? and how would one know if the cats were clogged? Sorry for all the questions, but I need some help........Thanks

 

It is a truck after all and the engine has a lot of inertia to overcome.

I can rarely screech the tires on my 1999 5.4L 4x4 extended cab unless I power brake.

 

Your driving a 6000 pound truck. That's most likely why.

 

Well the symptoms of bad O2s is reduced gas mileage for one. They are a 30k item. If you have more than 30k on the truck then replace them. I have 50 k on mine and suspect the O2s are the reason for some lost pep and gas mileage. From reading other posts the O2s can go bad and last a long time before triggering a code. They make the truck run rich hence the decreased fuel economy. Being smoked by a Focus is cause for concern.

 

You need to watch the O2 switching rates before flinging sensors at 'em. Replace them when they start switching lazily. Fuel filters are a maintenance item. Air filters are a maintenance item. Oil changes are maintenance items. O2 sensors are not.

Replace O2s when they get contaminated, usually by coolant if/when a head gasket or something fails, when the heater goes dead, or when they start switching slow.

 

That Focus probably weighs about half as much as your truck. It doesnt take as much power to get a small car moving as it does to get your heavy truck going.

I kind of doubt your O2 sensors are bad, youre just used to a fast car or something.

 

Hey screwed2002, dont compare a truck to a car and say it runs poorly. My buddy has a Ford Focus that is actually a quick little car. I found my truck was running poorly when climbing hills and just normal driving, I have yet to figure out exactly what the power loss is. Will get back on this situation.


Clogged cats make your exhaust stink like rotten eggs!

 

How do you monitor the switching rate of the O2 sensors? Will a scanner do it?

 

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