P0121, P0305, P0756 help how mcuh would it be to fix?

Question

its a 1996 grand prix. well uhh the other day it was raining bad and well the car stalled or w.e its called. after that the rpms got real high afterwords and also like from 30 to 35 the trans takes a long time to shift the rpms get real high and now changing shifts and shifts really hard what could it be. the fault codes were P0121, P0305 and P0756 plz help

how much would it be to fix. well around how much kinda like an estimate??

Answer 1

Sounds like it need new sparkplug wires and a throttle positioning sensor... its about an hour or so of work so that would be around $75 - $90 for parts and labor unless the mechanic is incompetant, than you'll pay more for their mistakes....

You probably had bad wires and when they got wet it zapped a few sensors and now they need replacing as well as the spark plug wires.. this is a rare event but in some setups can happen...

Answer 2

P0121 Throttle/Petal Position Sensor/Switch A Circuit Range/Performance Problem
P0305 Cylinder 5 Misfire Detected
P0756 Shift Solenoid B Performance or Stuck Off

But I'd bet you have moisture in a circuit somewhere. Impossible to say what it would cost, since it would depend on what they find. But do look for a moisture problem sending false signals.

Remember, the WD is WD 40 stands for water displacement.

Answer 3

P0121 is the throttle position sensor. Nearly all problems can be fixed by by replacing the TPS. Check with your local parts store for a price.
P0305, misfire cylinder #5. Bad spark plug, wire, or coil for cylinder 5.
P0756 Shift solenoid B Performance, or stuck off.
All transmission problems can be costly, but if the shift solenoid is stuck off and not defective otherwise, a good transmission additive might unstick it. Also check with your local parts store to see what is available. One that you add and run awhile and change the fluid and filter would probably be best. If the solenoid don't unstick, major repair will be necessary.