coug66

My vehicle was throwing a P0420 code. dealer says he shows both cats are low efficiency. $3200 job to replace them.
then I removed and reattached the bank two 02 sensor.
drove down the road and the dreaded VSC popped up.
I have been unable to get the VSC off even with resetting. I pulled codes and all the 02 sensors have codes plus P0100. reset.
I pulled codes now and a P0100 shows up. I install a cheap MAF but no change to the codes.
Symptom
car starts on the second turn of the key. will not accelerate above 3K?
fuel mileage seems good and I have replaced both 02 sensors on bank 2 ( drivers side)

I am starting not to want to trust the codes. I have a harbor freight code reader and a WiFi code reader with torq software.

I don't know that the MAF was the issue or that the replaced item is good.

nothing has changed with replacing the MAF sensor. still need two turns of key and wont exceed 3K?

any ideas would be appreciated. should I pursue resetting the VSC first?

The VSC came after I was removed and reattached the 02 sensor? perhaps in the process I moved the Y pipe causing the VSC to come on with a leak?

just looking for advice of what I should look at or pursue.



Vehicle VIN: Not present
Vehicle Manufacturer: Unknown
Vehicle Calibration ID: Not present

Current Fault Log
------------------
P0100: Mass or Volume Air Flow Circuit

Pending Fault Log
------------------
ECU reports no pending faults

Historic Fault Log

Romanova

Won't rev past a certain point is a classic sign of a clogged cat...

bloomwcjkl

PO420 is drivers side. P0430 is passenger side. I recently replaced my passenger side front catalytic converter. Decided to not go eBay cheap. $500 with install from my local shop. P0430 code gone.

coug66

I wonder how difficult replacing the cats is? It looks pretty manageable if I can just get clearance?

Has anyone done this job themselves. I was thinking about replacing the cats myself. I am an average home mechanic with basic tools.

I would love to know from someone who has done it how difficult it is?

bloomwcjkl

The hardest part seems to be that the bolts are rusted and break off. The indie shop had trouble with a couple rusted bolts that spun off and had to be drilled out.

If you have good tools, I think it is doable. Having it up on a lift would seem to be the biggest hurdle working underneath. I know you can buy both cat converters quite reasonably on eBay. I do not know about quality/lasting power. I decided to do it with a Walker brand. Somethings I can try myself. Others are just too much of a stretch.

Let us know what you do.

coug66

I checked the Y pipe to make sure it was not a pin hole leak. then looking at the bolts it appears to be a pretty reasonable job for my skillset.
I have impact sockets and am good at brute force jobs. Its the ones requiring technique and gentleness that I end up breaking stuff.


Total
2001 LEXUS LS430 4.3L V8
BOSAL 0961631 (096-1631)
Catalytic Converter$ 126.79 $ 253.58
DENSO 2344630 (234-4630) Oxygen (O2) Sensor$ 52.79

Shipping
Ground
$ 11.99
Order Total $318



I don't know if the Bosal catz come with seals? I will wait till they arrive and then if not buy them from the dealer.

Did the upper side of the cat need a seal?
I can also change my mind and just take it to a muffler shop with the parts. Happy to pay for labor if I find the right shop. If not it will give confidence to do it.

Romanova

Soak the bolts with PB Blaster or equivalent before hand if there is any rust. If you can hit the bolts with an impact, it'll be easy, though with a regular socket you should also be fine.
When you get the first old one out, compare it to the new repalcement as far as how the internals look.

Good luck!

tradosauru

I tried this method on a Mazda Protege with no ill affects.

coug66

Thank you for this, It might have helped but unfortunately it didn't work for me.
I tried the cleaner but it didn't clear the code. Thanks for recommending I figured if I could get the cats out I would want to replace verses get some more miles out of them. Once I pull the cats out I will try cleaning them as backups in case the new ones fail.
I will take before and after pictures.

I really like this car, I love the way it drives, so replacing a few items on it is no real issue to me.

coug66

Cats arrived and they didn't come with gaskets. looking around it appears factory gaskets are the best.

9091706059 engine side of cat
9091706078 rear side of cat

I ended up ordering them on Ebay. Dealer closed early today and is closed tomorrow. So I will wait a week and save $40.

imdking

iTrader: (1)

Good luck, man. Hope it all goes smoothly.

rkw77080

I've personally tried this home made concoction to remove my rusted O2 sensor. It worked great...

rkw77080

Be sure to use a 6-point (as opposed to a 12-point) socket to avoid stripping the nut. Another helpful thing to do is to heat up the nut to expand and loosen its grip on the threads. Use one of these disposable torches for this purpose.

tradosauru

I have removed O2 sensors by letting the car run for about 10 minutes and heating the exhaust pipe. This was after spraying the nuts with WD-40 the night before.

Have you removed your old cats? If so what did the insides look like?

coug66

I am optimistic about the nuts coming loose. The O2 sensors came out on my car with no issues. the nuts are not rusty, I have not had a single issue with rusted or overly tight nuts on this car so far.

I haven't removed the cats yet, waiting for the gaskets. When I remove the cats I will take pictures of the insides.

I just ordered the torches and an oil can for the acetone and ATF mix. thanks for the advice.