I'd lean more towards either a fuel delivery problem from a failing fuel pump and/or clogged fuel filter or maybe even a bad catalytic converter given the description of your problems. It would take more than 1 fouled fuel injector to cause your car to barely accelerate and it's not especially common for several injectors to fail simultaneously.
To rule out the catalytic converter, wait until the engine is COLD, then find the catalytic converter under the car and either shake it by hand or tap on it with a rubber mallet. If it rattles, then it's likely broken internally. If it's broken internally, it can drastically limit exhaust flow and cause all of the symptoms you're describing.
If the catalytic converter doesn't rattle around when you shake/tap it, then I'd take the car to a shop and ask them to check the fuel pressure. From there they can determine if it's low and if so what is causing it.
It can be the fuel injectors.
Check its cables, check spark plugs first. Sensors (MAF, O2) can be dirty as well, or you may have to change fuel filter. If problem remains, you should check the fuel pressure, such drop in performance would mean that multiple injectors fail that is not too common as said before.
I have recently had problems with one of my injectors in my '00 MR2 1ZZ, but my engine code was different, it said I had some engine misfire in 1 cylinder. I had a rough idle only, no problem when revved, and had a complete track day with it without problem.
Try asking here http://www.celica-club.co.uk/forum/index...
or here http://www.toyotaownersclub.com/forums/f...
My car is an '02 Toyota Celica GT, 5-speed manual
I think the fuel injectors might be either clogged or bad because:
1. It kind of has rough idle but its not always consistent like it only happens sometimes.
2. When I accelerate the car kind of jerks like it's taking a pause every second when accelerating. This also messed when starting from a stop because while in 1st gear I can push the gas pedal down an inch and slowly release the clutch and the car will start to accelerate then start to shudder like its going to stall, then all of a sudden jerk forward really hard.
3. My car can barely accelerate, at low gears my car can accelerate 'okay' but thats a big ok. Also my car is meant for low gear acceleration and sometimes I feel like I'm driving a Prius when its a compact sports car.
4. When in a high gear(3rd-5th) I can floor the pedal and the exhaust gets very deep and that sounds cool and I wish that's what my normal exhaust always sounded like, but the car doesn't move much. and if I'm going uphill my car accelerated so slow even if I floor it, that people will try and go around me cause i'm moving so slow.
5. About 2 weeks ago I got a P0171 engine code which is lean in bank 1. the light went off after 2 days. I though that it might be a vacuum leak but now I think it might be the fuel injectors because I took it to the shop and they found no leaks.
Someone Please Help!!
