2000 XLS feeling tired

[allblack2k]

I don't know how else to explain it, my X seems to struggle lately, it doesn't pull as hard as it used to, seems to have lost power, it's a 2000 XLS, with the 4.0 OHV, and 40,000 miles.
It was at the dealer about 3 weeks ago, they replaced, a sensor I can't recall the name but it's, small and it's located right past the MAF, on the outside. I know that's not very specific, but for the life of me I can not remember what's it's called, hopefully some of you more sabby X owners know what I'm talking about. Anywho as part of that they cleaned the MAF, the Trottle body, and the injectors, Or should I say, that's what was supposed to be done for the $180 dollars they charged me
Could it be the wires and/or the sparkplugs?
Please help guys, the other day an old lady in a Caravan took me at a light.

 

[allblack2k]

Please guys! I know there's got to be somebody outhere that can help me out.

 

[Majisto]

Hmm I don't know the OHV too well, but I may be able to help you anyway. What do you mean by feels sluggish? Do you step on the pedal and it just doesn't want to go, or does it go but it go but doesn't seem to have any ummph behind it?

Spark plugs or injectors should not be bad on such a new vehicle. You could get a compression test done to see if maybe something is leaking and lowering your compression in the pistons, but I think it's a much simpler problem...

Btw, was the sensor called the IAC (Idle Air Control valve)?

 

[allblack2k]

yeah it goes, but like you said it's got no "umph" behind
it.
That's what I thought about the sparkplugs, I'm pretty sure it was the IAC, I'll check for sure this afternoon when I get home and look at the service receipt.
I'll check into getting the compression test.
Thanks for the response.

 

[Majisto]

Originally posted by allblack2k
yeah it goes, but like you said it's got no "umph" behind
it.
That's what I thought about the sparkplugs, I'm pretty sure it was the IAC, I'll check for sure this afternoon when I get home and look at the service receipt.
I'll check into getting the compression test.
Thanks for the response.

Any word yet on this? I am curious to know what is wrong. I'm not an OHV expert, but my 4.0 is built on the same bored out 2.9 block at least