I have a 2006 IS350 with 186k miles. Several lights came on (P0430, P2757) so I took it to a mechanic who has really good reviews in my area. He spent some time going through it and came up with the following:
-The catalytic converter needs to be replaced. I'm also smelling exhaust fumes when I drive, so that makes sense. He says they are really expensive.
-The transmission needs to be taken apart to get more info, but it looks like the clutches or torque converters need to be replaced. He estimates about 4 hours of work just to diagnose the real problems.
He doesn't know exactly how much it will cost, but he did mention about $3 to $4k for both the catalytic converter and the transmission work.
When I look on KBB it is only worth about $4k. It has some scratches and tiny dents, so I had to select "Fair" for condition.
I discussed options with him, He said he sometimes has clients who are willing to purchase these fixer uppers with the intention of fixing and selling. He thought I might get somewhere between $1 to 2$k
I can't just dump this on Caraigslist because here in California you have to get a smog check before you sell it.
So, what do you think? Should I just let him try to sell it to one of his fix it customers and take a total loss on this? I love this car. If I sell it I'll be purchasing another IS for sure.
I would appreciate any thoughts on the subject.
Thanks.

 

Get a second opinion.

P0430 could possibly be an exhaust leak, or the cat itself. IIRC, there's a very common spot under the Y pipe heat shield where holes can develop. Another possibility is that bank 2 O2 sensor. Even if it's the cat, I imagine a muffler shop can just weld on a cheap aftermarket cat and call it a day.

2757 is a bit harder and probably needs an actual transmission shop to look at to diagnose. I vaguely recall there being some solder joint issue with the trans ECU on the 06's. So, it could be that, or actually the solenoids.

 

If you were planning on keeping the car long term, it may be worth repairing it. As mentioned, aftermarket CATS would be cheaper, and if it turn out to be just an exhaust leak, that's easily repaired by a muffler shop. As far as the trans, also as mentioned, I would get it diagnosed by a transmission shop, it would be a lot cheaper to replace the transmission with a used one than trying to rebuild. Keep in mind that repairing your IS will be cheaper than getting into another car, new or used.

On the other hand, if you are ready to move on, than this would be the time to do it, again keeping in mind that a new car means payments, and in many cases, ever for a used one

 

You have pics of your car? I’m in so cal & interested in buying it.

 

Lexus tech here in Florida willing to help if your interested and haven't decided yet what your going to do

 

I would definitely go with aftermarket cats as for the tranny I guessing a rebuild is around 2k. If you’re dead set on selling it, depending on exterior conditions I’ll buy it from you as is for parts so no smog certificate needed.

 

This. Never take the first answer.

 

I think this comment helped me make a decision. "Keep in mind that repairing your IS will be cheaper than getting into another car, new or used". I ended up getting the trans repaired for $1250. A solenoid had gone bad. I then took it to a muffler shop. They tried to get an aftermarket cat, but ended up having to get one from the dealer. I paid $1400. So, for $2650 may car is back up and running great. Thanks for all of your comments. I love my car and I think I'll keep driving it for a while longer.