legacycentral bbs

I am having a lot of trouble with off boost acceleration, mostly while "cruising", trying to maintain a speed while on an interstate highway, with light throttle (less then 50%) and keeping in vacuum...Ill try to explain what’s going on: I feel a big loss in power and the whole car shakes, it backfires very often also. If I give it more throttle, and create boost, it runs ok..but while its in vacuum, it has no power at all and its very hard to drive. It is almost random, and it goes away just as quickly and mysteriously as it started. I cant find any consistent factor that could be causing this to happen, but here are some possibilities:

- I recently finished my intercooler set up, so the air going into the engine is cooler then before. But i reset the ecu, so i assume it would have adjusted by now.
- My oxygen sensor doesn’t seem to be working, im getting that CEL, but this has been happening for a while, and the hesitation/vacuum problem has been much worse lately.
-it has been colder out, in recent weeks, but again that doesn’t seem like it should be a problem.

I am really confused by this, any help or ideas or anything is appreciated
Noah

Well......I would try and get the O2 sensor working again......and fix any other sort of problems/codes that are showing up.

Maybe do the active diag connectors. See if anything comes up.

Does the car lose power and try to stall, or does it just hesitate very badly?

Oh, forgot to mention, everything else is normal. It idles fine and starts fine.

No, it doesn't stall, if I push in the clutch while the hesitation is happening, the rpms will drop to the normal level, but it doesnt stall.

hmmmm.....I'm sorta out of ideas. I would like I said....get the O2 replaced......reset ECU.....& do active diagnostic.......see if anything else shows up......

You said it's intermittant correct?

Those are the worst ones.....I had an intermittant stalling/loss of power for about a year or more. Turned out to be an ailing MAF......during the winter it was not really an issue....temps got up during the summer.....much more of a problem.

Yea, same here. Thanks for the ideas!

..anybody else??

here is an update:

I have noticed the "hesitation" problem is getting progressively worse. I first noticed it a couple months back, and it occationally popped up every once in a while. But now it is constant. Now the hesitation continues no matter if its on boost or vacuum. Before, while at idle, it would "hunt" up and down for the appropriate idle rpm (between 400-1200). But now the hunting is much more pronounced, and it sometimes even dies

I'm almost sure its not the o2 sensor, but its possible. arrg