Engine issues - loss of power, sluggishness, CEL

[Hartman]

I know a fair amount about the common problems on OHVs but I can't seem to narrow it down on my truck right now. I was on the highway coming home, about a 110 mile trip, and the CEL came on for about 20 minutes then go off. Also, the truck has a pretty noticable loss in power. I could barely make 70, and when I had the cruise set, the truck would slow all the way down to 62-63 going up a hill, then slowly return to normal speed after getting up the hill. Also, if I was maintaining 60 mph for example and I try to accelerate to 70, the pedal felt real stiff and if i stepped on it to get it going, the tranny would downshift and shoot up to 3-3500k rpms. Its almost has if something is straining the engine.

I've narrowed it down to a few things, but I can almost certainly elminate some of them.
1. Clogged cat - would explain the loss of power, but I would think that this would effect acceleration more.
2. 02 censors - Not sure why the CEL wouldn't stay on all the time if this was the problem.
3. I checked the PCV valve - seems fine.
4. It is possible that the power steering pump is going bad, but I'm not sure how to test it out. Might be starting to seize and straining the engine.
5. The DPFE sensor was recently replaced. Fuel filter has less than 20k.

Any body have any ideas here?

 

[Hartman]

Also, at 70mph, I'm not turning any abnormal RPMs. Which is sort of weird.

 

[RickOTR]

How many miles on your explorer? Sounds like the CATS to me. Same problems that you are having. Trying to get my X to stay at or above 60 mph was a constant battle, on hills it was a nightmare. After changing out the CATS everything is back to normal.

 

[Hartman]

152k. Cats might be it. Not getting any abnormal smells though, which i thought was another sympton of clogged cats.

 

[BeauJ]

Mine was somewhat like this in my 00. I went from 275 miles a tank to 215 miles within a few weeks. I figured if it was the cats or o2s, I'd get a check engine light. Then I heard it won't always come on. So I replaced the o2s and my mileage went back up dramatically. But I still think my cats are ruined from the o2s being bad. Who knows, maybe I'll get 30 MPG when I replace (remove ) them.

 

[Hartman]

Thanks guys. I'm really thinking that my cats and/or 02s are shot. Gonna replace them hopefully with high flow cats and new 02s.

 

[94ZebraRanger]

I am having the same problems but after running for a while. I would loose power to the point of dieing. wouldn't stay running until after a cool down. I didn't get any CELs tho.

Tim

 

[Hartman]

Well it got better now that I found out I had an extra quart of oil in the engine. Not sure how that happened but I changed the oil and the rear brakes (needed new rotors pads and calipers) and its running a lot better now.

 

[jonagne]

I've been having the same problem intermittently for about a year. '97 XLT w/ 86k. It almost always happens after driving on the interstate for awhile (30-40 miles, although last week it waited until 175 miles). I first noticed it when accelerating out of a toll booth, and had no power at all until I pressed the pedal all the way to floor, at which point it downshifted and started to accelerate normally. Last week I had the cruise set at 70, and when climbing a hill (not a steep one) it decelerated all the way to 55 before downshifting and accelerating back to 70. The cruise steadily moved the gas pedal almost to the floor. The engine sounded like it was bogging down as if I was in too high a gear. The CEL light flashed on/off 4 times and remained on.

I initially thought it was a transmission problem, but everything checked out perfect (plenty of fluid, good color, etc.). I was starting to suspect a bad engine computer as this is sort of what happens when mine went on an '89 Volvo, but isn't that usually an all or nothing event?

Maybe I'll change the O2 sensors, and/or take a look at the CATS (I'm assuming catalytic converter). Of course, the Ford dealer is clueless, so any further information would be appreciated.

 

[BuffaloXplorer]

Cats can be tested with the use of a temperature-sensing gun. A working cat will be considerably hotter in the rear, as the conversion of the gases causes a temp rise.

I was hoping my 10mpg was attributed to bad cats, and i was disappointed when the muffler shop told me that they were A-OK!

You could call around - a decent exhaust shop should have the gun - or you can invest in one yourself from a hardware store - but it needs to be able to read HIGH temps. I'm sure Summitracing has them.

 

[V8BoatBuilder]

What was the Code??

 

[Hartman]

OBD1 = worthless.

 

[BeauJ]

Well it got better now that I found out I had an extra quart of oil in the engine. Not sure how that happened but I changed the oil and the rear brakes (needed new rotors pads and calipers) and its running a lot better now.

Do you change your own oil? Not trying to be a smartass, but how did you notice you had an extra quart?

 

[Hartman]

Oil level on the dipstick was way over the crosshatch. I think the last time I changed my oil, I put 5 quarts in even though I didn't change the filter. I also cleaned the IAC and throttle body.