Hesitation when pulling away

[anubis1980]

Hi i have a 99 Yaris 1 litre. Where to start?! well a while ago i noticed the performance had dropped and my mpg had dropped too. took it to a garage and he said it sounded like it was misfiring. so he hooked it up to get tested and he couldnt find any error codes. he said it also drove like it was flat...

he cleaned everything (his words) well when i got it back it was the same. i left it over night woke up went to work and the mpg was back to where it used to be ages before! so he had fixed it. well the last couple of days ive noticed when pulling away the car hesitates, then picks up, mpg seems the same and ive also noticed (as he did ) a noise that MIGHT be hissing although i cant be sure. the plugs are new, new air filter. Im stumped ive cleaned the MAF sensor, checked plugs again to make sure they are all ok (all same light tan colour). So if anyone could please throw some ideas my way id really appreciate it :)

Brett.:iono:

[746watts]

dirty injectors maybe? add some injector cleaner to a 1/4 tank and see will that help.

[RedRide]

Yes, dirty injectors are the first thing I would suspect also.

[anubis1980]

sorry for the late reply, thanks for the ideas... well things started to get worse. first when i put my foot down the car almost stalls, then bumbles then pulls off a LOT worse than before. then my engine light came on. took it to garage today, he said it had 3 codes on it! one was MAF sensor, another was (i think) oxygen sensor and the other was mixture too lean. kind of annoyed me as he took it for test drive after resetting teh codes and said it was fine so didnt bother to listen to the engine. if he had he would have seen how it almost stalls when you put ur foot on the accelerator. I called him back and he said well it was fine when i tested it but we need to wait for the light to come back on again as its going to be expensive to fix so he needs to check first what the engine code reads (he thinks me taking out the maf might have put that code on the history)

Also when i first got it i was having idling issues so i took the maf off and im sure it ran ok (with a light on though inside) then i put the maf back (testing to see if MAF was the issue) and reset the light and it was ok. so i thought id do the same this time, ie eliminate the maf but it starts then stalls and turns off without the MAf in. he said that it should run without the maf but richer as he does this to BMWs and Audis to test them (and like i said im sure i ran it very briefly without a MAF before to test if the maf was working)

sorry for the long rant any help would be appreciated.

Thanks,

Brett.