I've searched a ton and can't find the location of the temp sending unit for my car (the coolent temp is sitting on C all the time). Does anyone know where this is located on the 3.0?

 

Its burried behind the motor on the rear coolant cross over pipe. Its a coolant pipe that connects both cylinder heads, the sensor sits on top of that. There is a little plastic clip that holds the sensor in, pry the clip out (don't lose it) then pop up the sensor. Some coolant will spill out, if you take the coolant cap off MOST of the coolant will come out so don't do that.

 

thanks for the location, I'm supposed to pick up the part in about an hour. I've purchased the spacers, and I'm guessing while it's the easy out fix to the cats, it's going to be a pain. I'm sure I'll be on here asking about that as well. I'll be ordering the Bentley manual and working from it. Thanks for all the help, I love the car-this cat thing is a pain though.

 

The O2 sensors are actually pretty easy to get at on the 3.0L thankfully, when you look behind the motor you will see an O2 sensor located in the center of the cat, those are the after cat O2 sensors on the 3.0L. The before cat O2 sensors are located almost at the back of the cylinder head, you can only feel them by reaching behind the head, they aren't visible. So thank god you don't have to take out the upstream O2 sensor.
The funny thing is, i bet your car would still pass smog if the check engine light isn't on.

 

Wait, so you're telling me there is something that isn't a pain to repair on the 3.0? sweet! I had given up hope
That's what I keep reading, and one of the reasons I don't mind putting in the spacers.

I've been wondering if the temp sending unit isn't also to blame for this. If it was bad, then wouldn't the car run rich, and screw up the post cat readings? I'm guessing there is about a 5% chance of this happening....but is it possible?

 

Yes it will run very rich, and it will cause a hard start concern.

 

Back to post 17, you said they would probably give you your money back and take the car, rather than go for new cats.

I think I would give them the car and look for another one.

I don't know if Fla has Emissions or safety inspection. My state, PA does. Car I bought had major problem within 2 weeks. Timing belt tensioner, led to bent valves, replace engine, etc.

Neither here nor there on that. BUT, when the mechs pulled the tranny for another problem, found melted cat, unplugged cat cable, and busted boots on both half shafts.

Defective cat is emissions violation. Busted boots are safety violation. Car was sold to me with brand new Safety and Emissions inspection stickers. Gave me leverage to get them to pay for repairs on both problems, with threat of calling State Police Safety Officer who Audits Inspection stations. Minimum 90 day loss of license, thousands of revenue, and most of that labor, hence net to the garage.

My mech says there is no such thing as "as is" in auto sales in PA. Dealer sells you a POS, you have recourse.

BTW, PA, not FLA, I found a shop to make up and install a new cat for 280 complete. Inspection station reimbursed me for that, I am sure with input from the dealer. Dropped it off on Friday, picked it up on Tuesday.

Cheers,

George

 

I think I have decided to keep the car but your points are well taken. I do believe that the car was sold to me with the known problem, but since it was a lexus dealership-I really think that they just thought it was an o2 sensor. They did replace the sensor for free for me. Florida has screwy laws in this area. When you buy a car in Florida "as-is" you are stuck with it, regardless of what happens. I am playing off of the idea that they knowingly sold me a car with a default, and hid that default. With all that said, I am probably just going to keep the car and do the work. I know that they will not do the 3K for the cat change, and I don't know where I could find a shop to do the cat removal and replacement (is that called piggy?). The 280 dollar deal sounds awesome....wish I could find that...

 

I replaced it last night, things are working pretty well-except that the outside temp is about 3 degrees high. I'm guessing I need a vag-com to adjust that, and I'm going to have a to wait a while before I can spend the cash on that.