so confused please help

[01cav2.2]

i have a 2001 chevy cavalier 2.2 ohv it has been a great car but for the past 6 months the car has had a wierd hesitatation stumble buck dont know what to call it but noo codes i replaced the throttle position sensor did a fuel injection service plugs wires and coil and still it does it evry couple weeks just once i have an after market intake and header i thought maybe it could be the o2 sensor cause its been relocated to the down pipe i do notice that my car is running very hot just not going to the max (fans cool it back off im just soo confused any advise will help oh i have to tell you what its doin first its basicly when coastin at lower speeds almost stopped and than stepping on the gas its starts jumpin than comes out it like nothings wrong i do see the trac off light come on than go off sometimes but not when the problem is occuring may it could be a solenoid on the trans or IAT sensor or coolant temp sensor just wish i knew please help thanks

[Jacfourteen]

I'd start by checking for vacuum leaks, take some carb cleaner and spray around vacuum lines if you hear a change in the idle then there is a leak in that area. Also, when was the last time you changed the air filter, with the price of fuel I'd do that just for fun. If you can't find any leaks then I would suspect tranny problems. the easiest thing to start with is a trans filter and fluid change. then go from there. good luck!

[Zeifer]

Might be a plugged converter. Unscrew your top oxygen sensor (before the converter) and drive it around, see if that does anything. Make sure there are no wires or meltables nearby though.

[Jason/RKBA]

Check the fuel pressure.

[01cav2.2]

i work for sears auto we did a fuel injection service (run rite) and replaced the fuel filter i just did a trans flush and filter 3000 mi ago the air filter is brand new its on my short ram intake i have a header that moved my o2 sensor from the header position down to the down pipe which caused me to cut it splice it used heat shrink and 16 gauge wire but it worked but sometimes the check engine and track off light come on for p0130 but than go out or just the trac off light but than goes out after a day i was thinking maybe it might be a cat myself but we did temp test before the cat and after and it was running the way it should but when i first start the car i get a like a gassy exhaust smell the prob only happens when ive been driving in the city ill see the lights red hit the brakes while im coming to a stop the light will turn green so ill get back on the gas soon as i do she will start bucking for a couple secs than will take off i figured id get a damn code by now im really frustrated i almost put my hand thru the dash last night i was so pissed here is a list of services ive done or parts i replaced: TPS spark plugs NGK iridium ix spark wires and both coils throttle body cleaning fuel injection service new fuel filter trans flush and filter please help

[Zeifer]

When my converter was plugged, it wasn't overheating. I'm just suggesting you pull off the top oxygen sensor and see if it runs any better, because the exhaust wont have to go through the converter. The new position of the oxygen sensor shouldn't matter, as it is still before the converter.

[01cav2.2]

but what other issues would i get from a plugged converter i thought it might be like shift lock solenoid on the trans i know the 3 speed auto trans had that problems but i havent heard anything about models with 4 speed trans or my torque converter could be fouling up im hoping my timing chain didnt like skip a tooth or something or have a bad chain tensioner which is causing slack in the chain i cant afford that right now im still stumped on it the cat cause i would like the to know if it cause other problems besides the hesitation like the car runnning more hot but this car has always went past the middle even after doing coolant exchange and new radiator it still ran hot as hell