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The FT readings you posted above are good. I would not be concerned at all about the fuel mixture occurring in that car.
Thanks for your assessment.
So my car really does just need new cats? I've had both off & they appear in good condition. Can they wear out with showing physical signs of damage?
Can they wear out with showing physical signs of damage?
Yes and no. What you see when you look in to the end of the converter may be different than what you would see if you were to cut away the metal body.
I've seen portions of the catalyst burnt away in the middle but appear normal on the end. More often I see them melted or clogged from rich bursts or burning oil.
What most people miss is that those codes can be caused by things as simple as a dirty air filter, dirty MAF, loose or corroded battery ground, More often than not, its an overlooked air leak. From your description, I doubt the problem is in your cats.
Yes and no. What you see when you look in to the end of the converter may be different than what you would see if you were to cut away the metal body.
I've seen portions of the catalyst burnt away in the middle but appear normal on the end. More often I see them melted or clogged from rich bursts or burning oil.
What most people miss is that those codes can be caused by things as simple as a dirty air filter, dirty MAF, loose or corroded battery ground, More often than not, its an overlooked air leak. From your description, I doubt the problem is in your cats.
I can see the front of the whole catalyst through the air/fuel hole & it looks great. I'll keep trying to find something else.
I can see the front of the whole catalyst through the air/fuel hole & it looks great. I'll keep trying to find something else.
I keep finding a small amount of oil puddled just behind the throttle body. I replaced the rear valve cover & PCV
a few months ago after I found some of these engines had issues with the PCV sucking oil. It's just as bad now. This pic is after I stuck my finger in the puddle so it was much worse.
The short hose between my PVC & intake was very loose. I had replaced all the other hoses months ago & forgot this one. If $.95 hose is all it needed I will be thankful!
So my check eng light came on,
and it gave me these two codes
(p0420 bank 1 catalyst efficiency below threshold)
(p0430 bank 2 catalyst efficiency below threshold)
some people told me its my o2 sensors, others that i need a new catalytic converter.
Have not taken in to a shop yet, what do u guys suggest i do to rule out either catalyst or 02sensor ???
Has anyone had the same codes?
(2001 gs 300)
160k
When I got my Lexus gs300 about 1 year ago. I had that same code and my car will studder when driving pass 3k rpm. So I replace my cat and my car still have the same code. So I did more research and I found that my MAF ( mass air flow sensor was clogged or bad ). Try that and let me know how it goes.
Listen to me. I had this problem. I changed out all my cats from Sewell Lexus and that cost me ALLOT. But in all reality, cats don't go bad that often. Here's the inexpensive response your looking for. Change ALL your o2 sensors and ALL the gaskets BEFORE and AFTER your cats. Also if you have a good mechanic, tell him to check the wiring to the o2. Make sure they're not all deteriorated bcuz that can cause an interruption in signal to the computer and cause the CE light to come on. Due to it not reading the o2 sensor properly. But yeah, new o2 sensors and gaskets before and after. DONE!
Just looking at the odds, its very unlikely that both your cats failed at the same time. Its also very unlikely that A/F sensors on both banks failed at the same time. Odds are, something occurring long before the cats is effecting engine performance, making the exhaust too rich. MAF, MAP, IAC, vaccum leaks, FP regulation.
Just looking at the odds, its very unlikely that both your cats failed at the same time. Its also very unlikely that A/F sensors on both banks failed at the same time. Odds are, something occurring long before the cats is effecting engine performance, making the exhaust too rich. MAF, MAP, IAC, vaccum leaks, FP regulation.
I replaced the rear O2's with new Denso units. Apparently the new Denso splice-ins were not quite enough. It's been 300 miles since the CEL went out. Everything seems fine. Way cheaper than replacing cats!
I'm getting the P0430 code. I purchased an ODBII scanner and recorded the data in the picture below for the bank 2 sensors. I had my car in park with the engine running for this. Can anybody tell from the picture below if I have an issue with the bank 2/sensor 2 O2 sensor? The 2 spikes on the B2S2 (purple line) occurred when I revved the engine. The line never moved other than during those 2 times. I'm not sure what it's supposed to look like though. Any help would be greatly appreciated.
02-26-16, 07:51 PM
