Engine lugging under power

I own a 04 chevy aveo and it runs fine at an idle and if you rev the engine when it is not in gear. A few minutes after you begin driving it feels like it is lugging and or missing a compression. Normally below 2500 rpm and in 1-3 gear. I initially put a few bottles of heat in the fuel tank thinking it might be ice buildup but that didn't solve the problem. I then changed the spark plugs and inspected the wires. From everything going on i suspect the fuel pump/filter which is in the tank. No error codes are being shown and or tripping at any point.I don't have to much knowledge in mechanics, so I guess my question is am I on the right track or has anyone else had this problem. Any help would be much appreciated.

I don't think its a fuel problem. You can tell by reving it up farther. If it gets worse as RPMs go up (keeping the engine loaded), its going to starve for more and more fuel so it should get worse. If its only happening below 2500 rpm I don't think it would be fuel related. However, running a bottle of injector cleaner never hurts.

Did anything happen to the car previous to this change? Some service work or anything?

Nothing happened to it this has been a problem that has been getting worse over the past few months. I went through like 30 pages of past forum questions and decided the that when I changed the spark plugs I should've changed the wires. So I went home and took the plastic sheild off and had my wife look at them in the dark and saw 3 out of 4 wires sparking to the head. After a quick wire change it ran like a champ. Im guessing because they are routed in that channel and due to the high heat from the motor they melted and started shorting out. Thanks everyone who looked and even more for Daox for posting a possible solution. Hope this helps someone else out in the future. Glad it was not a more cost and time consuming fix.

Woohoo, glad you got it figured out. Nice job. :headbang: