black944 turbo

My car hesitates when the O2 sensor is connected. Right when the car switches from closed loop to open loop (when the boost gauge hits 0 and starts to boost). This is most noticeable at 1/4 throttle or so, between 1800-2500 rpm. I just replaced the O2 sensor( same thing with the old one that is why I changed it) and I tested the TPS at the DME as clarks garage says. I don't know what else to do with the car except to take it to the shop. I called them and I am penciled in for Monday. Any help before then would be appreciated. The only thing I can think of is the DME itself is bad. Thanks a ton for any help.

black944 turbo

The car bucks or jerks hard in the transition it only happens for a second. Sorry I just thought I would try and clear that up. Hopefully someone has dealt with this before.

fast951

I emailed you directly.. Rotate the MAF around a bit and note any difference.

black944 turbo

Thanks John, I will try this out tomarow and report back to you. I appreciate all of the help. If all else fails, Then it will go into the shop on Monday.

azmi951

I just had sommething similar happen.

Check to make sure the O2 wires are not burnt or shorting. That is what happened to mine.

black944 turbo

The wires going to the DME? I just changed the sensor, I know that end is fine and it did the exact same thing with the old sensor. Thanks.

fast951

Try the MAF rotation. If it does not help, contact me directly before going to the shop..

black944 turbo

Will do. Thanks again, John.

azmi951

ok. mine were tosted from the connector to the sensor.

OriginalSterm

My car is doing almost the exact same thing. It does seem to go away after a good 20 minutes of driving though, when the car is good and warm. Not sure if it's the same thing, but I may rotate my MAF meter to see if this helps. What location should the sensor be at (12 o'clock, 3 o'clock, etc)?

J Chen

Hmmm,
I posted a thread last week with the same problem too.
Will try the rotation & see what happens.

roadrunner

John,

Why does rotating the sensor have an effect? I hope this is not a "trade secret"...

thx,
Jay

black944 turbo

I tried to rotate it as far as I could and not much if any dif. Any other ideas. I hope someone can figure it out. The car is just miserable right now.

fast951

The MAF is to eliminate any turbulence before/after the sensor. Some MAF sensors are more sensitive to the slightest bend in the piping... This may not be the isse here, but one of the first things to try..

Too bad you don't have a setup to fata log the MAF signal..