Need help with sensor issue

SyntheticShield · 06-16-2009, 11:47 AM

Me and my wife just bought a 2003 Santa Fe. When I brought it home I proceeded to start cleaning things up, including the engine bay (Im kinda anal about such things). Well in the process I got one of the rear spark plugs soaked and it started misfiring.

Since I was planning on doing all the tune up and general maintenance I went ahead bought new plugs. Could not find a plug wire set anywhere locally so I bought some MSD Street Wires, 8mm, 500 ohms per foot. I reused the OEM boots and connections. Pulled off the upper intake mani and got all that done, replaced the Intake gasket, throttle body gaske (had to make that gasket as no one had one locally).

I got everything back together and it all went fairly smoothly, though Im still baffled by the design and having to take off the intake mani to get to the rear plugs and equally baffled as to how water got down into a rear plug (#5) to cause a misfire. Ive power washed engine bays for many years and have never had an issue.

At any rate, when I started it back up, the misfire was gone but the idle seemed off, seemed like it was loping just a bit, like it had a performance cam in it but just barely noticeable.

Well the check engine light was on and the 4WD warning light was flashing which it was not doing before I started the work. I took it to autozone and they pulled two codes, P0123 & P0222, indicating the Throttle Position Sensor was bad. The wanted $200.00 for that sucker. I have NEVER paid more than around $30 for a TPS.

So I thought I would post up here and see if there were any other things that could be causing that code. I can see where if the TPS is truly bad it would cause the 4WD warning light as the computer uses the signal from the TPS for transmission control and shifting. But good Lord, $200??

It seems to drive and shift fine other than the slight loping at idle. I pulled the connector for the TPS off and found it was not even clicked or locked onto the sensor. I thought at first maybe it was not making good contact so I cleaned it with some electrical cleaner and tried to connect it back up and it would not go onto the sensor fully. Upon further inspection I could see that the weather seal on the connector was out of whack and apparently not holding its shape. I took it out and was able to get the connector fully onto the sensor. However, that has not fixed the issue.

So if anyone has any input, I am all ears. If it is truly the TPS is there any place I can get that thing cheaper? Perhaps a good used one off a totaled Santa Fe or something like that?

Anyway, sorry for the long post and thanks in advance for the help.

SyntheticShield · 06-16-2009, 04:33 PM

I cleaned the connectors with electrical cleaner and I cleaned out the throttle body. I disconnected the negative battery to clear the code. When I put everything back together there are no check engine codes and the 4wd warning light is off now. However, it seems it still idles funny, like its about 100 RPM low or thereabouts. I took it for a drive and it ran well, no shifting issues or anything and its not trying to stall (earlier, when I cleared the code by disconnecting the battery, when I drove it it was trying to stall and did once but started back up and I just had to keep a little pedal in it when I stopped to get it back home).

I also, while I had the throttle body off, hooked up my multi-meter and tested the TPS and it changes resistance throughout the entire swing of the throttle plate, no dead spots that I could detect. So the only issue that appears to be left is the slightly low idle. I dont know if that is the result of perhaps a marginal TPS or the fact I disconnected the battery cable and reset the ECU.

Either way, before I spend $200 on a TPS I want to be dang sure thats what it is, but based on the testing, it doesnt seem thats what it is.

Does anyone have any suggestions?