Cheap vs. expensive tps sensor.

[IGot2Board]

Hello all, I am a new owner of a 94 Lexus ls400. I bought the car from my brother about a week ago and he says it ran well for him. He recently changed the O2 sensors which cleared a CEL that he had. However he wasn't driving it much and it had been sitting for awhile. When I got it and drove it home it seemed to run fine. But about 2 days later I have the issue where if I step on the accelerator any more than a little less than half it will stutter or just flatline the engine to about 1000 rpm. I've been reading through some of the forums on this site and seen people talk about the problems with the ECU capacitors so that was the first thing I pulled. It had looked like someone had gone through that process before because some of the clips in the glovebox were already missing and the ECU looked brand new inside with no sign of leaking caps etc. Then I moved onto replacing the fuel filter which did look really rusted and old but that also did not help. So now I am moving onto the tps sensor. At my local AutoZone the cheapest one is about $100. But I have seen some online for as cheap as $12 up to about $30. So my main question is there really much of a difference between these. Some of the cheaper ones seem to still get good reviews being put onto other vehicles that they'd fit (Toyotas Volvo's etc.) Also if anyone has any other insight on what causes this issue would be great. The vehicle has 245k miles and runs perfectly otherwise as long as I'm light on the throttle. Sometimes I will get a quick flash of the Trac off light when this happens. Not always so I don't know if it's just coincidental or not. Thanks in advance for any input anyone has.

Eric

[LSPaul]

Welcome! 

Did you pull the codes from the computer to determine what the fault code is (so you can dig in?  Also, go back and check the basics--caps, rotors, plugs, wires. At that kind of mileage, there's certainly a chance that they've never been done.

From my experience, the ECU capacitors can look just fine but still be bad.  Replacing the capacitors took care of the issues I had (bogging down like you're experiencing and the check engine light code of 47, which  is for the secondary throttle position sensor for the traction control system.

Good luck!

Paul