JoeSuff

Update: All's good, Got to 111 miles on the new sensor and no eng light resurfaced.  I decided to do the Downstream o2's this weekend.  Read a couple threads where best practice would be to to have them all done together.  I'm assuming the holes in my exhaust causes the o2 failure to being with.  I used a set of Denso this time since it looks like everything from underneath the car is a Denso part.  

90 LS purchased w/61K.  I'm now rounding 65k miles.  I've been getting 16.1-16.5 mpg on my Fill-ups.  Mostly Suburban w some HWY.

 I had an exhaust blow fixed between the cat flanges.  Yesterday, I finished replacing both sets of Down Stream o2 sensors ( i had done the upstream a couple weeks ago for code 25 & Trac).  Currious to know if my MPG's go up now.  I haven't done a fill-up since.  I did notice prior to my test drive the car would sporadically drop RPM's when coasting around 40-45mph.  It didn't do this, but one test drive means nothing since i noticed Engine Lights can take 50-100miles before showing again if they come back.

Well i was home for the day.  Thought id try and snap a pic of the engine harness for the o2 sensor, ponder what i could do before dropping $150 for the OE part.   I started with the passenger upstream since that was the easiest to see.  Once i had the harness off i thought id give a go mounting the NTK sensors once again, armed with the knowledge that Rock and no sites i posted to seemed to have any knowledge of problems.  ^^Mr Bob Exhaust Gasses being the only person to offer any personal input.  I'm guessing that the car so old most people have abandoned  following.  

Anyway with a lot of persistent wiggling and the help of a set of long reach bent nose pliers i was able force and finally seat the replacement sensor.  Of course then i had to unclip it, pull out the threaded original and then insert the aftermarket once more.   Im on my 4th restart and 35 miles.  The light hasn't cycled on (yet) .  If i get to 100 miles im hoping ill be okay.  

Incase any other First Gens should follow heres a few pics of the Upstream o2 Sensor connection

Thanks,  just confirming what they already knew.  Sometimes just easier to see.

90 LS400 64k miles. Service engine (code 25) and Trac light on.

Previously when I bought the car I had a small leak at the rear cat flanges to exhaust pipes. An exhaust only custom shop cut and replaced the bad metal. I was hoping having the offending pipes replaced would fix the service engine since it was right between the two sensors on both sides.  I reset the lights but they came back.

I purchased a set of NTK o2 Sensor (for some reason i thought the were OEM got them confused with the Denso)  When I went to install the sensors I was unable to seat the replacement plug into the engine harness. I pulled them and saw the seperator difference. I can't see into the harness on the engine but it's the only thing that seems to make it so I can't seat the electrical part.  Neither sensor was able to click into the harness but the both screwed in.  I put the original sensor back in with no problem.

I called rock and they said ALL including Denso have the same (+) like style connector and not the (-) like I pulled. I'll buy OEM if I have too But at 3x's the cost I don't wanna spend the money to have to splice harnesses.

Anyone else ever have issue?

My '90 LS 400 C Pillar lights:  The map light (push button) only turns on when depressed.  The Entry light only turns on with the corresponding door being opened.  None of the C Pillar lights turn on with with driver door or the overhead switch being turned on.

On my 5 month new to me (64K miles)  90 LS400 

From Rock i picked up

ADVICS AD0476 and ADVICS AD0488.  

I've got about 3K miles on them.   Feel fine to me. I drive calm but like to toss the car when the road is open.  I don't know about how aggressive the grab needs to be when i read through all the different forms about brake upgrades.  My winter rims don't show any brake dust compared to what was on the car and i have slotted rear rotors.   And they are quiet however, i have hardly any milage on them.

Prior, I took it in to lexus when i bought it just to update the records and go over its service history.  They wanted $1400 for new brakes job front and rear.  They said what was on the car was not factory pads.  I thought i read the ADVICS were factory.  But im new to the game so i could be wrong.

 I recommend the Brembo disc that they have on clearance.  15 dollars a rotor for brembo is crazy.  I order a second set on my next order just to have on the shelf.

OOPS saw i had drifted from the 90-92 thread.