oldManTan

so i have code 25 on my 92 SC400, i've looked around a bunch and narrowed it down to the O2 sensors, my TRAC and ABS lights are on too and someone somewhere said that that's a good clue towards the O2 sensors being faulty. my questions are, where are the sensors, 2 main ones, and what kind of sensors should i be looking into? i found these on sparkplugs.com says they're OE

and then also some universal Bosch ones

i'm gonna stop at Autozone and Oreillys today too and see what i can get there as well. anyone got any tips on this stuff? i've looked a lot for a DIY on how to replace the sensors and haven't found anything with the upstream sensors, everything is for the exhaust ones.

fourstars

o2 are located on the headers. there are a total of 4. on each side of the headers, 1 is before the cat and the other is after the cat. its located 3-4 inches away from the cat bolts. testing it should be easy. but with no tools, i would use the other side o2 sensor to see if its throwing the same codes. if it is, then its a bad o2. if not then u got more testing to do..

oldManTan

you're supposed to check for resistance with a multimeter right? i saw on Lexls there was a DIY but it didn't really make much sense cz the guy had some pretty bad pictures and couldn't tell which wires he was checking. i'll just keep looking. anyone else got any ideas?

fourstars

i would download the FSM for the sc400 online. it is free on lexusextreme.com.. u just need to search, once downloaded u can see the instructions in how to test the O2 and everything else related to it..

SC400slide

iTrader: (11)

I don't test them, I just replace them. Lexus SC's eat them like candy.

oldManTan

yea i'll order these right away, my car just started hesitating like hell, even died at the light while in drive and when i started it in the morning. this just came out of nowhere. you think the 02 sensors could do that? also on really low throttle, when cruising at any speed the car like chugs, almost feels like the breaks are dabbed a little, it used to happen to my xb sometimes but rarely, could be the TPS right? i still need to clean the throttle body, probably never been cleaned for 216k miles.

EDIT: forgot the link