TPS causing shifting issues?

[NV00EX]

Roughly a month ago my 2000 Civic EX w/auto transmission had the CEL come on and started having really erratic RPM's and would almost sputter at low speed/slow acceleration, during quick acceleration it had no issues. I had the code pulled, it was P0122(Throttle Position Sensor), bought one on eBay, installed it, unhooked the battery, hooked everything back up, start the car, after 5 seconds, CEL is back on. I drive the car, and the original issues are gone, no erratic RPM's or sputtering. But, now the car isn't shifting properly, it is waiting until 3800 RPM's to shift, doesn't down shift under heavy acceleration(I.e. going uphill). During rapid acceleration the 3800 rpm shift is perfect, but during slow acceleration, it seems like it should be shifting much sooner, 20 mph in 1st gear has the engine screaming. Another issue I have noticed is when I'm slowing down, the car shifts from 2nd to 1st hard, like a thud, it is so hard, it feels like I slammed on the brakes during the downshift. So today I had the CEL code pulled and it's the TPS code again. Does this make sense, what else could it be?

 

[00siboy]

Have you checked the signal wire from the tps to the pcm? It could be damaged or you could have a loose connection somewhere giving a low voltage reading and setting the code.

 

[NV00EX]

I haven't checked the wire, I will now though. But, it's odd that you mention low voltage, my dash lights strobe, I can "control" the frequency of the strobe based on how low/high the AC fan is set to. Could this be interrelated? It's done this since I bought the car.

 

[00siboy]

Sounds like your alternator is charging low. If the blower motor is turned off do the lights stay on more consistently? Any electrical load on the car puts more of a load on the alternator, and if the alternator is going bad it can't keep up with the demand. Has your battery been drained at all? I would suggest getting a starting and charging system test done, whether at a shop or a parts store that will do it, and get a printout of the results.

Alternators can have erratic low charging conditions that can cause driveability issues, so it would be best to start with that first.