My Celica drives very sluggish after warmed up

[2001RED]

I notice my Celica drives very sluggish after the car is warmed up. When I gas the car, seems like it doesn't want to go when. I mean gas as in normally pressing on it, not gassing the daylights out of it. It drives really sluggish. Weird thing is that it drives perfectly normal when the car is cold. It's a 2001 GT auto w 18k miles. Never mod, bone stock. I never pumped anything below 89 Octane and I only go to Shell or Chevron, so I doubt it's the gas. I pour in a bottle of fuel system cleaner every 8k miles, it seems to drive fine for like a few days but the problem comes back. What is the problem here?

[GTS LAID]

you might have a dirty mass air flow sensor or intake air temperature sensor.. each one of the symptoms will lead to you feeling a bogging as a result of running lean on fuel.

as for why it only does it when its cold... thats a strange thing for it to do... maybe its got something to do with cooling system in the car.

[Willis5050]

I have heard that using fuel system cleaner a lot can actually be bad for the engine. I seem to remember that using it was a big no-no for my old SE-R, but I don't remember any specifics. Who knows, perhaps someone else knows more details....

[DavidYan]

my guess is that it is running too lean, it runs fine when its cold beacuse most cars are programmed to run extra rich when the car is warming up.

[Griffin]

You need to get a scan tool on it and look at what the fuel trim is doing when it warms up. If it runs perfectly fine cold, then all of a sudden the performance degrades when it heats up, thats an indication of a closed loop problem, possibly an O2 sensor thats rich biased and causing the system to lean out.

Griffin