ok short story i have a 1999 tiburon fx with the 2.0 engine lately i have been loosing all power on the road. i can be driving normal when suddenly its like if some one cuts off gas pressure to the engine and even though my foot is on the pedel the car starts to slow down as if i took my feet of the pedel. took it to the mechanic and they changed the MAF will this fixed the problem for about two weeks. Now the problem is back and we cannot find a solution. We changed a new maf, fuel pump, throttle body sensor, fuel filter, complete tune up, wires, sparks, and oil change, when in park the car reves fine but once in drive has lost a lot of power and sometimes drives fine with no problem and sometimes looses power. The new thing i discovered today was that if you disconect the battery for the whole day and then put it back car will drive fine for about two days with no problem but then problem returns can some help me.

 

It may be the ECM itself. When the battery is disconnected, the ECM resets and then begins to learn your driving style. I'm going to assume every time the car was worked on the battery was disconnected. The new parts didn't fix the problem, the reset ECM did. To test this theory, disconnect the battery every time the power loss happens and see if it correctes itself after the battery is connected again.

 

i have treid it two times already and yes the disconnect did fix the problem both times. the only thing i have to add is that this all started after i upgraded to a aftermarket jdm header. My original flex pipe or intermidiate pipe as they call it broke in half well the dealer wanted $100 for just the pipe but i found what they call is a 4-2-1 racing header that came with a new flex pipe for only $80 with shipping on ebay the new header elimanates the catalytic converter that was on the old header basically its 4 straight pipes out of the engine that splits into two pipes and then into one pipe that connects with the flex pipe and then to the back of the car. After i did this the car ran great with more power for about 2 months and the ths is when i first started having this problem. the first time the battery did not get disconected they just changed the MAF and the car was like brand new. But it only lasted for like 2-3 weeks and now the problem is back and got worse the mechanic changed out so many parts but it didnt do anything and when he connects the OBII code thing to my cars computer for some reason they have problems comunicating with each other he can even get hit code detector to reset my computer. the check engine light also comes on with a bank 1 sensor 1 low voltage they have changed out the 02 sensor twice and the light goes away for about 1hr and then after driving for some time it comes back.

 

I think something happened to the ECM. But that's just a guess. That or the ECM can't compensate for the higher flow header and lack of cat. Personally, I'd find a tuner that can adjust the computer to work better with the header.

 

Can any one help or give me an idea of what to do. WOuld buying a new computer solve myproblem. Still haveing the same problem and yes when i reset the computer the car will run fine for like 1-2 days then starts to loose rpm's again. not sure what to do i see a lot of people on here have the same acceleration problem with thier tiburon loosing power at low rpm;s or slow acceleration. Is there a fix for this really can afford to buy a new car rite now.