Bad TPS symptoms, replaced TPS

Hey guys, I need some help. I have a 1998 XJ with a 4.0. It isn't idling correctly, missing, and not wanting to shift correctly. It is throwing a P0122 code for TPS voltage low. I've tried two different TPS units from Napa and cleaned the throttle body. The problem isn't all the time but intermittent. Any ideas what to check?

Check the wiring for any chafes / funkyness all the way back to the ECM - but don't be surprised if it is just bad sensors, either.
My TPS gave me an occasional hiccup and funky torque converter lockup behavior.
I replaced it and all was well for a month. The replacement TPS died.
Replaced it again under warranty - that one lasted 6 months and was crap again.
I finally put the factory TPS back in.
The point I'm illustrating and which others will chime in on as well is that replacement sensors are very, very frequently crap right out of the box.
So check your wiring for any issues, clean the connector that plugs onto the TPS - and don't be shocked if a sensor from the dealership fixes the problem.

Did you use NAPA's Mileage Plus Electrical or NAPA's Echlin sensor? I've heard nothing but good things about NAPA's Echlin line. The last Echlin part I bought was a reboxed dealer part, with the Chrysler star. Otherwise, I agree with yossarian.

It is the echlin line. When back probing the connection I'm finding that the tps has the correct volts with no flat spots

One thing I did find is when checking the voltage through the wires when not connected to the tps the middle wire has 4.4 volts coming through it. Could that point to an issue with the the pcm?

Bump

The TPS is not a Hall effect sensor. It does not generate its own voltage. It is supplied voltage and then an output signal is sent back to the PCM based on throttle position. It sounds like it is fine.

I had a thread about TPS about 2 months ago. Mine was intermittent and mostly failing hot. Had the low and high voltage TPS codes. Many times sensors will work fine cold and fail hot and many times we find ourselves not wanting to work on hot engines so we test cold.

You might try the dealer part. If it fixes it, I'd make NAPA give me a refund regardless of what their return policy is.

The weird thing it's mine is acting up only when cold even thigh the sensor tests fine

Ok it is not the tps, I used two different known good parts and still has the same issue. Both parts were oem jeep parts.

Ok I'm just going to take it to the dealer, can't figure out what it is.

Be sure and follow up with the thread, let us know what it was.