arfghan

If anyone has removed the ECU from a 1995 GS300, PLEASE give me input on how & exactly where.
In the 94, I'm told, it is under the carpet, passenger side front floor. Not in my 95, I've checked. The other suggestion was under the dash, same side.
I have the bottom dash/knee panel off. Minimum of 3 items under there that look remarkably like the ECU pics I've seen! I don't want to remove more than I need to.
Do I need to remove more cowling or whatever?
Is the ECU enclosed in some plastic holder (I see lots of heavy white plastic under there.)?
Tips please!
ESPECIALLY if you have actually done this on a 95 . . .

Salcedo90

Unless it was moved then it should be on the passenger side toward the front of the floor pretty much like under the glove box up against the wall

Nixspeed

Its on the floor, under the carpet where your feet would be under a black plastic cover. I believe there is 3-4 10mm bolts/nuts holding it in. Its 100% covered so kinda easy to miss.

arfghan

Well, shoot. Was all set to find and swap out the ECU.
Before I did, though, decided to double-check. I took the new battery out of one of our classic trucks, and popped it into the gs300. Tried to run the codes again .. and this time it worked!
Very clearly blinked out code 21 (Main O2S & Heater Signal).
How dumb do I feel? Even though I had previously jump-charged the lexus battery, it obviously wasn't up to the 11 volts needed to run codes.
So NOW I need to identify the o2 sensor and replace it.
TIPS??
Looks fairly simple, as long as I identify the right unit, heheheh.

Nixspeed

There is 2 main o2 if I remember right. Its on the passenger side of the motor sticking out of the exhaust manifold. If I were you I would buy both main o2 and replace them both. Also I recommend only the denso direct fit. If you buy the parts its should be very easy to spot them looking in the area I described. If I recall you'll need to remove 2 12mm nuts per sensor. Try not to lose the gasket between the sensor and manifold. You can reuse it if the new sensor doesn't come with them.

Glad you got it figured out.

arfghan

So ... I replaced both upstream O2sensors. MYSELF! The only things I've ever replaced before were fuses or a battery. But how do you guys with guy-size arms and hands do this stuff?? Even with my smaller-size girl arms/hands, it was really, really snug in there!
Anyway. Got it done.
Cleared the codes. Started the car, Wha Hoo! Started right up, no check engine light on.
Ran in to get my license to go for a test drive; when I came out it had died. Would not start again. Checked codes. NO codes displaying. It was firing, turning over, not catching.
Ok. Gave it a couple hours. Went back out, reattached the battery (I disconnect the neg when I leave cars sitting) and this time it started up. Ran okay, idling.
I'm leary of a test drive now. Can't afford to have it conk out on the long driveway and block things so we can't get out. I guess I will go start it and sit in it and see how it goes.... maybe I could do laps back and forth beside the carport?
Thanks for all the help!
What do you all think? Just tune up stuff? Fuel filter? (I looked for an in-line but did not see one.)
Should I start a new thread for help on this?

Nixspeed

Fuel filter is under the car on the drivers side in front of the rear wheel under a metal heat shield. Its all hidden but easily accessed with a 10mm. I would definitely do a full tune up.

Good job on swapping out the sensors.