Hesitation when accelerating after gear change, goes away with battery disconnect

[BoxsterInTheSun]

Originally Posted by blue62

When you disconnect the battery the DME resets it's fueling maps to the default settings.
That's why the hesitation is gone for a while.

I am just making a.....very broad guess here..... but it could be the MAF sensor or your O2 sensor's
both sensors "age" and their signal slows down so the response from the DME to the fuel injectors will have a very slight lag.
It will not throw a code until "signal slow down" from the sensor exceeds a set limit in the DME.

So you need someone with the proper test equipment to test the sensors.
and the knowledge to run and interpret the tests correctly.

This is really helpful actually. I had cleaned the MAF sensor a while back, suspecting it might be that, didn't make any difference though. I'll take a look at the O2 sensors next, I hadn't considered those as possible culprits.

Thanks again!