hamhead

Reason I think its probably not plugs/filters/etc. and really is the o2 sensor like the dealer says is that it happens when the car is warm, since most newer cars (assume the Tib does as well) doesn't use the o2 sensors until they are warmed up. Odd that it works o.k after 3000RPM plus though. A bad filter/plug/wire/etc. would cause suckiness throughout the whole powerband, not just lowend.

Dmitry

ECU works in closed loop (reading O2 sensor and correct A/F mixture to 14,7:1) when at idle and when on cruising.

When you open wider throttle or driving at high RPM - ECU switches to open loop (not reading O2 sensor) That can be reason why it works ok after 3000 RPM.
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Try to accelerate with WOT from 2000-2500 RPM, what will result be? Will the car bog?

Gspeed22

At WOT around 2000-2500Rpm, the car bogs, though-out all gears.

Post by Dmitry
When you open wider throttle or driving at high RPM - ECU switches to open loop (not reading O2 sensor) That can be reason why it works ok after 3000 RPM

That the same issure my car is having, once at high rpms its fine.
Well im still gonna change the plugs and wires, haven't changed them since last year.

silvertibbs

I think Dimitry is on the right track with that. Hamhead suggested O2 Sensor's and he is prolly right. Replace those and see how it goes. Shouldn't be too bad of a cost. I smell an upgrade to a wideband sensor possibly.

**EDIT**

Just found a troubleshooting chart for this exact problem.

http://www.hmaservice.com/webtech/default.asp

Gspeed22

One more questions:
which O2 sensor is it, upstream or down stream???

silvertibbs

Most likely downstream, as in what Dimitry suggested it reads that sensor and decides whether or not to add/subtract fuel. So I would say that one first.

Gspeed22

thanks silvertibbs