hey.....I have a problem my car had its tranny rebuilt about 8 months ago and it has a 12 mo/12k mile warranty from the dealer. Recently I have been driving the car and its been jerking alot. The Rpm gauge goes up and down around 2-4 rpms without any increase in power. The car doesnt pull hard at all. I took it to the dealer on monday and they told me since its a tranny problem its covered under my warranty that its something inside the tranny they need a few days to check it out. So today i get a call saying that my tranny is fine, that some sort of Throttle sensor or accelerator sensor is bad that i need a new one and it would cost 147 dollars for the part and about 140 to install. Any advise?
could it be my Maf sensor?
And i dont know how they figure my tranny is fine because even before i got this problem my transmission jerked rough out of first gear.

 

This is just a guess, but I'm guessing they are talking about your TPS. "Throttle position sensor". Alldata has the price listed @ $116.53. Part # 226204M511. Usually dealers have a slight mark-up over MSRP unless you tell them you know the price. When the work is done at their shop, the parts counter usually adds a bit more of a mark-up on top of that.
$140 labor to install is a bit pricey. Flat rate is 6/10 of an hour for this job. (The tech may have gone heavy on the ink and wrote the repair job as an hour labor) Depending on what they charge per hour, .6 would be from $50-$65. They must have charged from .7 to an hour diagnosis. Really all that needs to be done to find that this is bad is hook up a scantool and look at the voltage coming from all the sensors. The TPS is about .82 @ idle on most cars and about 4.5-4.9 @ WOT.
The TCM takes info from several inputs. TPS, MAF, ETC analyzes this data and tells your tranny what solenoids to activate which in turn sends hydraulic pressure to certain areas of your tranny locking/unlocking certain members of your planetary gear set. (Basically what gear to engage)
If your TPS is reading 1.5 volts intermittantly when it should read 3V, then all of a sudden jumps to 3v it thinks you have the pedal down just a little, then down further which will cause downshifts for more power and firmer shifts to prevent slippage.
As far as your last sentance goes, as far as they know your TPS (or other faulty sensor) is causing this problem as well and won't know it jerks our of first gear without the faulty sensor until they fix this problem and test drive it. It may have been going bad for a while and this may fix that problem as well, it's hard to say until the work is done.. Either way if they are talking about your TPS just go in there and tell them the only reason you brought it there is because you thought it was going to be covered. It's hard to say if they'll still charge you diagnosis or not, but IMO an hour diagnosis is a bit excessive, he should have been able to hook the scantool up and see right away the TPS sensor data was incorrect. It's a 5 minute job, most people flag 1/2 an hour for it. (verify condition, roll it onto bay, plug connector in, etc)
If it's an intermittent problem I'd say an hour diagnosis is fair.