a Water pump underdrive pulley. The o2 sensor is probably the original. I think i am going to replace that next. Which one is the best one to buy? When banging on the cat what should i listen for?? I will read about cleaning the MAF, because truthfully this is about the third time driving it since i cleaned the filter so that might be it. Edit: Just read about cleaning the MAF, i am goin got do that and unhook the battery and see if that makes a difference, if not i am going to do a new O2 sensor. How do i go about checking fuel pressure?

as for decrease in power, no not really but when i was at the track my first few runs were all 16.1'* then after a few they went to 16.2-16.3. So coming from those numbers yes it looks like a decrease in power now you mention that and i take a look at my numbers.

I would replace the O2. ACDelco only nooo bosch.

do you have a part number on it. Also it is a pretty staight forward thing to do right. Just unscrew the old one and screw in the new one, or are there any tricks to it?

Techinfo has your part numbers. No tricks. Use a big wrench or O2 socket. Easier than a spark plug.

i am not seeing it in the tech info but i did find this. Is this the right one? http://www.rmsautoparts.com/proddetail.php?prod=AFS75

is that it?

yes, that is the one.

my bad to bump a month old thread...just wondering if the problem was figured out, I had the same issue last month at it turned out to be a flaky spark plug wire...manifolds were red hot.

The changes in track times mean nothing. You can't determine a decrease or increase from a couple tenths run on different days in different conditions.

An underdrive water pump pulley won't gain you much if anything (trust me, I'm running one), but it will cause you grief with cooling. Where did the pulley come from? Did you modify the torque-axis mount? What size is it?

Glowing manifolds is typically a lean condition. Is your SC pulley stock? What'* your fuel pressure?