sethjon

You will NEVER get 20 in the city.

305ls400

changing this sensor improve my mpg but is not a big difference but it helps

dvourthis

I did this and did not notice much change at all. and sethjohn is right, 20mpg in the city would be nice but no way. i get about 18-22 average with a light foot and a leaking EGR tube.

trukn1

Bumping this thread since it most closely resembles my problem. Have a CEL, pulled the code with the result being 25. Gonna change the ECT and see if that addreses the problem. Car is not knocking and is running very smooth, so I am not suspecting that the knock sensors needing to be changed at this point. On a side note, for those who did this and it did NOT fix the problem and needed to change the O2 sensors as well,,which ones were pulled? Know the LS has 4 of them. Just wondering which ones you replaced, as these sensors are better than $100 each.

deanshark

If you do need to change the O2 sensors I'm pretty sure it's the main heated, which would be the fronts, 4 wire. (that's what the manual says) If you don't want OEM parts you can get them alot cheaper at Parts Train dot com. And even more cheaper if ya get the ones where you put the connector on and heat shrink. The brand "Replacement" are $30 for the main.

trukn1

Dean,, def appreciate that. This is what I needed to know. Will see what she is doing once I replace the ECT and determine if I need to go that route to fix as well. I have just had a MASSIVE amount of work done to my LS. List includes having the engine and tranny pulled, new motor mounts(front and rear), strut rod bushings(finally), engine was in pretty bad shape and had to be replaced. Used an SC400 one and had to have everything transferred over to the "newer engine", as it was not a direct swap(LS and SC 400 only SHARE the same block and heads,,everything else off of the motors needs to be converted/swapped), new spark plugs/wires/rotors(distributor cap was still pretty good), new starter, front and rear main seals, intake manifold gasket, valves adjusted, timing belt and water pump installed, deleted the EGR (pipe was cracked and new one was a ridiculous amount of money to replace)) cleaned the throttle body, industiral strength lower ball joints(fronts), and all new vacuum lines(cracked and brittle). Was a fair amount of work. Still have to change out my driveshaft bushings(both of them) as well as replace my outer tie rods and then install my cross drilled/slotted rotors and pads; just want to address this problem first as I don't want the lean malfunction to linger any longer than necessary. Then can move on to replacing my tires and finally the headunit; sooo much 'little" stuff to do now, just not enough time to do it, especially on my schedule.

deanshark

Wow that's alot of work. I didn't realize that driving a truck paid so much. Do you have enough time to do it yourself with your job and all, or did someone else do the swap? I can see why ya want it to be right, with all that work. Hopefully the ECT will take care of it. Good luck.

trukn1

LOL,,,,if you believe that driving a truck pays that much, well then "might I interest you in a bit O land that I just might happen to have for sale?" LOL!!! I had been stockpiling parts little by little for awhile now, and once the tax money came back, finally pulled the trigger to have it all done. Had a buddy of mine do it (Toyota/Lexus certified) and he did it on the side for me. Took him a little while to do everything but it got done. Next big project is gonna be the exhaust (my Y pipe has some holes in it, and was temp patched up to quiet her down,,,sounds like I am running glass packs for the moment). gonna yank all of that from the cats all the way back and start fresh.

SkulCracka

researched .... and the autozone is made by wells. will be picking one up tomorrow to go in with the o2 sensors i got. now if i can just find some cheap ramps. LOL

SkulCracka

ok got ramps will return them to wall world when i am done. passenger side o2 came right out new one went in no problems. driver side will not budge.... have srayed it down with pb buster severral times still wont budge???

so i moved on to the coolant temp sensor. i can see it. have almost everything removed. but dont want to break anything. ran out of day light and using the flashlight sucks. will try to finish up at least the temp sensor in the morning an leav the o2 to the mechanic. worst part is the o2 that i was able to change was not the one giving me the code. do you think if i let teh engine get hot the o2 would come out ? or should i just let the mechanic use a torch on it?

any way back to the temp sensor. can someone show a picture of were the two bolts are for moving the coil pack. maybe i just didnt have enough light to see them? thats alot of bolts just to get to this sensor LOL

deanshark

Skul; I don't have a pic of the bolts for the coil but there are two, one is on top to the right, (the one you can see) and the other is underneith the coil to the left. (hard to see) I used a 3" extension with the 10mm socket. Comes out pretty easy but make sure you do not drop that bolt, it can fall inside the timing cover and then you'd be screwed.
I don't think heating up the engine would get the O2 sensor hot enough like a torch. Ya know, you can probably buy a small can of propane and a cheap torch kit to heat it up so you can get it out. Cheaper then bringing it to a mechanic and you'll have another tool for future use. That's the way ya build up a large tool collection. Good luck.

SkulCracka

thanks Dean..... found them two screws this morning. replaced the temp sensor. old one fell apart like otehre here. ended up with a few left over screws. LOL car is now finaly like new. shifting and all that others have said about changing this sensor.

got mechanic to remove the other o2 and install for 15 bucks.

deanshark

$15 labor to change an O2 sensor??? Holy ****!!!! That's a deal I'd like to get, well worth it.
You'll notice a big difference with the new ECT. Some have noticed worse fuel mileage right after changing it, (including me) but with me it was b/c I was driving it harder b/c of the quicker response it gives.

SkulCracka

ya i got lucky. i will be going back to that guy. im trying not to throttle it more. lol need those extra miles. shifts like hot knife thru butter now and yes it was doing that right after the temp sender cahnge and before the o2 sensor change this morning. went about 30 miles then reset the ecu after filling up. wanted to wait to make sure of what i was noticing and to make sure the CEL did not come back. i was only averaging about 13-15 mixed city/highway. so this should bring me upto rated spec of the car.

qewani1

What is the OEM part number For 2000 LS400
I found one with part number 892230030
am confused now! help!