Fire from exhaust !!
05-24-17, 01:18 AM
#31
Driver School Candidate
Thread Starter
Assuming the catalysts remain removed, my post above (#17) stands because since your computer is not receiving the expected signal from correctly operating catalysts, your car may be in some sort of a limp mode. And the limp mode is causing this issue. From what I remember from the video, it seems to hit an rpm and hold there, it won't shift. Well, maybe you're doing something that the factory would have never expected.
Of course Lexus expects that catalysts will eventually fail. So, they create some sort of limp mode to put the vehicle in, to prevent further problems (of which I cannot imagine) when a catalyst fails. I think it's possible since your catalysts are missing, your ECU computes that as a failure. In 99.9% of the cases, most owners would fix the problem (the failed catalyst), and NOT be trying to run their car up to redline. I'm not saying you're doing anything wrong or bad, more power to you. I find it interesting. But, Lexus engineers may have programmed in some sort of limp mode, and it will shift gears just fine ... except with 100% throttle, the shift point may be programmed to be at or near redline. However, if you are indeed in some kind of limp mode, its possible that the limp mode program prevents the vehicle from hitting redline. And since the Lexus engineers may not have imagined they would have a customer with a catalyst "failure", paired with a driver throttling it at 100% to redline, maybe the 2 conditions are fighting against each other.
Hard to explain. On one hand, the shift program may not be affected by limp mode, and is still waiting on redline to shift to the next gear because the throttle pedal is at 100%. On the second hand, the limp mode (if it exists) is preventing the vehicle from hitting redline. Thus, the problem you're experiencing.
Jason Oliver
Of course Lexus expects that catalysts will eventually fail. So, they create some sort of limp mode to put the vehicle in, to prevent further problems (of which I cannot imagine) when a catalyst fails. I think it's possible since your catalysts are missing, your ECU computes that as a failure. In 99.9% of the cases, most owners would fix the problem (the failed catalyst), and NOT be trying to run their car up to redline. I'm not saying you're doing anything wrong or bad, more power to you. I find it interesting. But, Lexus engineers may have programmed in some sort of limp mode, and it will shift gears just fine ... except with 100% throttle, the shift point may be programmed to be at or near redline. However, if you are indeed in some kind of limp mode, its possible that the limp mode program prevents the vehicle from hitting redline. And since the Lexus engineers may not have imagined they would have a customer with a catalyst "failure", paired with a driver throttling it at 100% to redline, maybe the 2 conditions are fighting against each other.
Hard to explain. On one hand, the shift program may not be affected by limp mode, and is still waiting on redline to shift to the next gear because the throttle pedal is at 100%. On the second hand, the limp mode (if it exists) is preventing the vehicle from hitting redline. Thus, the problem you're experiencing.
Jason Oliver
No I don't, there'd be a lot more codes than just one...you literally might have 25 codes if the Ecu failed. Plus I watched your video,the engine didn't seem to be running too poorly. If the ecu was bad you may not be able to get the car going over 25 miles an hour.
I'd take it to someone who can simply hook it up to a scanner, pull the code, walk over to their software program that they have, punch the code in...and see what it says to trouble shoot first. You have no cats, so fuel/fire is going to come out of your tailpipe (the cat would stop that). Maybe you have a leaking injector? Maybe the O2 sensor is telling the computer you're running lean and it's dumping fuel to correct it? Maybe you've had exhaust work and it's leaking oxygen and throwing the O2 sensor off? Who knows? Get it checked out.
I'd take it to someone who can simply hook it up to a scanner, pull the code, walk over to their software program that they have, punch the code in...and see what it says to trouble shoot first. You have no cats, so fuel/fire is going to come out of your tailpipe (the cat would stop that). Maybe you have a leaking injector? Maybe the O2 sensor is telling the computer you're running lean and it's dumping fuel to correct it? Maybe you've had exhaust work and it's leaking oxygen and throwing the O2 sensor off? Who knows? Get it checked out.
I will fix the O2 , and i will come back with result
Thank You Doublebase
05-26-17, 06:38 AM
#32
Former Sponsor
Removing the cats should not affect driveability or fuel trim tables. Downstream O2 sensors only should monitor the catalytic efficiency and set a code if they fail, that's about it. The upstream sensors affect fuel trim, affect fuel economy and can cause misfires. The worst that's going to happen by removing the cats is a check engine light that will keep you from getting an inspection sticker...that and the fact that it's illegal in the United States. And the computer can easily be fooled into believing the cat is still there (but I won't get into that, LOL, an easy Google search would show you how).
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