I bought an '04 aztek a couple months back with 209k miles. I was unaware of how many issues it had.
Things I've already replaced:
Catalytic converter
Front struts
Both rear wheel bearings
Front brakes
Rear bushings
The check engine light comes on and off occasionally and the engine ticks and whines. I replaced the oil already and it did improve the performance slightly.
Issues I'm still having.
ABS light is on, and AWD is disabled.
I have to be very gentle with the pedal to make the car accelerate and if I slam on it the RPM's shoot down along with the speed (at around 25-30mph). The same thing happens up hills no matter how gentle I am but it happens so much worse. I was told it was an issue with the traction control and that replacing the wheel bearings would fix the issue. The wheel bearings helped a lot but it still is happening. Also, there's a rattling noise coming from what seems to be the rear end when the RPM's and speed shoot down. I'd really appreciate some advice, thanks.

Hi All!
I am a newbie here bought my Tek about the end of Sept. and Absolutely Love it!! I bought it because 1. It was a great deal, and 2. because it was so unusual and One of a kind...just my kind of rig!! Always like to have something that no one else has!! And No One around these parts has one!!
Anyho...Bought my '05 AWD Tek with 139,000 Aprox. miles on it new it needed tires...so after about a month finally broke down and got some...and have to say before continuing with story and question she ran like a Champ and Great Fuel mileage for an AWD and 6 cylinder...and Great handling!!
So, got new tires put on and within about 3 mi. after tires were mounted started to get a slight shimmy, vibration, and just felt different in handling...called dealer and they said that it could be that a weight could have fallen off, and if it continued to bring it back; well, I kind of got used to the handling of new tires and didn't think anything else about it.
O.k. on to the rest of the story, Now about two weeks after new tires the ABS and AWD Disable lights came on, checked on here and saw that that typically means that rear hub bearings are going out, or brakes, so I got on ebay and bought the hub bearings. Then about a week after The Lights came on it started do the deceleration thing with loss of power when pressing the gas pedal to gain speed quickly, and Way Worse when going uphills and shortly thereafter brakes started feeling mushy. So, I finally got to take it to my mechanic and he and his brother got to looking at brakes and I told them about the other things that it Could be and they asked me approximately When it started happening and I told them that Actually everything started AFTER tires were changed.
One of the brothers thought on that for a bit and came to the conclusion that it could Very possibly be that the Torque on the nuts were not all the same, and the other brother who has previously worked at tire shops, said you know? a lot of times when the guys put the tires back they don't check torque and just air wrench them on and call it good. So, they talked it over and figured that with all the sensors going crazy and the fact that brakes were feeling mushy(because of torque, tires would move in and out and make brakes feel that way)That that was the problem, so this week I am taking it back and we are going to jack it up and go through everything just to be sure and what im hoping is that if we go through and adjust torque that my Tek will be back in business.
Will report back with findings, and if anyone else has had this problem I would Welcome any feed back as now my Fiance thinks that I have bought a "piece of Crap" money black hole. Which im certain that it isn't.
Will state once again Love, Love, Love my Tek!!! Nicest most comfortable driving and riding "car" I have owned in Years!!!
Thank you for any input any of you can give!!
Teklvr1

The loss of power with acceleration, having to be "careful" about accelerating, problem going uphill, etc. sounds like a Throttle Position Sensor gone bad.  The engine literally doesn't know where your foot is on the gas, and you can get erratic behaviour like that.  Might be worth checking.

In case my problem (abs & trac lights are on - fwd '01) ends up being ebcm, and not just a sensor, does this eBay guy  still exist? I had trouble finding it with a search, maybe if I knew the exact part number?

An easy, and extremely cheap solution to see if the ABS traction control system is the issue with your acceleration issues, is to just disconnect the ABS sensors at each wheel. This will make it so the ABS/TC system wont engage because it has no real time data to process. If this fixes your acceleration problem, you then know its something in the ABS/TC system. If it doesnt fix it, hook your sensors back up, and look towards the engine.

You could have a faulty ignition module, one of the 3 coils could be bad, I cant remember if these have a MAF but that could cause the problems, TPS (throttle position sensor) could also, and just a simple tune up could fix the problem (plugs and wires) (I know, not that simple on the aztek).

With the issues you have explained, do you have a check engine light on? If so, head to your local autozone, and find out what the codes are, and report back.