Engine Hesitates when high load without shifting

I have replaced the MAF sensor and uploaded the data as you asked.

I have to ask, Is the car performing worse with the new MAF?

I'm in the process of compiling charts and it looks like the Calculated engine load does not like that sensor.

Your total fuel trim is under 10% but predominantly NEG in all ranges, Old DATA and New DATA, so the PCM is compensating for a Richer condition.

SO far I think your B1S1 is sluggish, and I still think your fuel pressure is varying too much.

I'll post some graphs tomorrow for you.

It's interesting, at first I thought the car ran better with the new MAF sensor, but now I'm starting to think it isn't. Around 50mph and up the car seems to have a slight hesitation constantly, like it's struggling for power at low rpm. Do you suggest I remove it? I was thinking maybe I just bite the bullet and go to the dealer and buy one even though they'll charge me like 200 more than what it's worth.

Finally, Some Charts!

I'm not even sure where to start with this one, because there is so much data. These charts are what I believe to be the best representation of the data. If you would like the worksheets I can provide them.

Lets start with the New and Old MAF Sensor

Lets ASSUME, that the new MAF is doing it's job correctly(which I believe it is because higher g/s were achieved under load per given rpm).

The New MAF made your Total Fuel Trim trend NEG, reducing fuel for what the O2's perceive as a RICH condition. I think the new MAF data has helped identify problems that were otherwise more difficult to detect.

Remember this is graphed data, however the PRE-o2's do switch slow. Only a scope can verify this.

B2S1 shows lean trends in data sets(new/old) the B2S2 is proving it. This trend is common with the OLD and NEW MAF

B1S1 is not as bad as B2S1, but they both display slow switching.

Now, lets look at the CALC Load charts, did the new MAF ever bring out some up/downs, very erratic. I think this helps magnify the sluggish B1S1 and B2S1 and possible fuel issue.

The fuel pressure vs rpm charts show huge difference in fuel pressuring between the old and new MAF. A lot more drop outs.

?????Which Direction to go???????

I am concerned you have a fuel pressure problem( not a volume delivery problem), albeit either the mechanical step-up, low pressure pump, or maybe the sensor is erratic.

The o2's are sluggish, but are they telling the truth?

Before tackling a Fuel Pressure issue, I would first verify the O2's are capable of reacting to an induced RICH/LEAN condition and the PCM reacts with either NEG or POS STFT.

Create RICH condition, introduce propane into the air stream, both B1S1 and B2S1 shoud respond to 0.8+ volts almost next to immediately and the PCM should Start making the STFT go NEG both banks.

Create a Vacuum leak (LEAN) condition, both B1S1 and B2S1 should respond <.0.3v immediately and increase the STST on both banks.

I would definitely want to address B1S1 and B2S1 first, they could change a lot of data and also rectify the hesitation, before tackling the fuel system.