Do Not Sell My Personal Information Jump to content

Recommended Posts

Hello everyone! I’m pretty new here, and before I ask my question, yes I’ve been throughout forums seeking answers and have tried a few things but now I feel as though I need advice. 

 

Recently grabbed a ‘93 LS400 that’s been misfiring. I just had the alternator and belt tensioner replaced but the car did stall out on me due to very rough and low idle. Check engine code comes up for the mass air flow sensor and TPS, both of which were replaced and recently adjusted by my mechanic. I had heard that if the catalytic converters were glowing red that means that they were possibly clogged, possibly oil in the cylinders leaking(?). I’m not sure, I’m fairly new to these vehicles in general. 

One thing to keep note of is, the check engine light is illuminated. When I give the car gas it shows major power loss, however halfway thru second gear the car starts to pickup/ maintain speed and the check engine light goes away. Once I come to a stop, or even let off the gas for a bit the CEL comes back. Complete stop brings the rough idle back. I did read that the ignition coils could be to blame as well. I changed the one dead center in the engine, but not the second one by the battery.

 

 

My question is should I be weary of the cats? My plan was the yank them and simply straight pipe the car on back. However efficiency is all I want now considering I haven’t had time to even enjoy the car since I purchased it 😟 

 

 

1993 LS400 

188,114 Miles

 

4C8F23A6-9B59-4433-9D52-9F3ACD46A08C.jpeg

Link to post
Share on other sites
On 8/4/2019 at 11:27 AM, SvpremeKai said:

Hello everyone! I’m pretty new here, and before I ask my question, yes I’ve been throughout forums seeking answers and have tried a few things but now I feel as though I need advice. 

 

Recently grabbed a ‘93 LS400 that’s been misfiring. I just had the alternator and belt tensioner replaced but the car did stall out on me due to very rough and low idle. Check engine code comes up for the mass air flow sensor and TPS, both of which were replaced and recently adjusted by my mechanic. I had heard that if the catalytic converters were glowing red that means that they were possibly clogged, possibly oil in the cylinders leaking(?). I’m not sure, I’m fairly new to these vehicles in general. 

One thing to keep note of is, the check engine light is illuminated. When I give the car gas it shows major power loss, however halfway thru second gear the car starts to pickup/ maintain speed and the check engine light goes away. Once I come to a stop, or even let off the gas for a bit the CEL comes back. Complete stop brings the rough idle back. I did read that the ignition coils could be to blame as well. I changed the one dead center in the engine, but not the second one by the battery.

 

 

My question is should I be weary of the cats? My plan was the yank them and simply straight pipe the car on back. However efficiency is all I want now considering I haven’t had time to even enjoy the car since I purchased it 😟 

 

 

1993 LS400 

188,114 Miles

 

4C8F23A6-9B59-4433-9D52-9F3ACD46A08C.jpeg

If the cats are glowing then they are working overtime to burn the unburnt fuel. The misfires are probably the culprit sending too much unburnt fuel into the cats.

Link to post
Share on other sites
  • 2 weeks later...

its either being significantly overfueled which is a possibility with the error codes, or plugged cats.  if it were a gm, i'd suspect the cats, but being a toyota, its probably not them and more like a  26 year old engine computer problem.  the best way to do this would first check the easy parts, maf if you have a scope, tps can usually be checked with a multimeter.  after that if you can check the pressure in the exhaust do that, usually requires drilling and tapping a hole or removing an o2 sensor.

Link to post
Share on other sites
  • 2 weeks later...

Catalytic converters glowing red simply mean that they are working properly because the unburnt fuel is burnt there. The problem is that the feed back system is not working right. Since you already have replaced the mass air flow sensor and and TPS, remainings are ignition related parts, injectors and the ECU. I would check the ECU first since it uses infamous QAS capacitors inside and they fail after aged. There were many people like you who were having the same problem with you and they now are happy with new capacitors.

Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...
  • Similar Content

    • By MillerCAT Corp
      In response to the increase in cat theft, we’ve engineered a 304 STAINLESS-STEEL Cat Shield™ secured using tamperproof screws for the 2011-2017 Lexus CT200h vehicles. The Cat Shield™ has also been thermal tested to ensure proper heat dissipation for the prevention of overheating issues.
      To top it all off - we'd like to offer this 10% discount code "LexusOwnersClub" to all the members in this forum which can be used at checkout (www.catshield.com) or use this link for automatic discount application: https://catshield.com/discount/LexusOwnersClub?redirect=%2Fproducts%2Fstainless-steel-millercat-2011-2017-lexus-ct-200h-cat-shield%E2%84%A2.



    • By Logan pool
      I took my 98 ls400 to a mechanic because the car would not accelerate unless it was completely floored, I had already replaced the throttle position sensor and I took it to the mechanic to replace the acceleration position sensor, after he replaced it and reconnected the battery the car wouldn’t even start anymore and he was getting codes for something like a security problem, and the security light was flashing but if I remember right it has always been flashing. There was also a code for the ECM (computer), I have no idea what the problem is so anything anyone can tell me would help, thank you.
    • By DavidLS
      Anyone know what this is ? 
      next to the drive train. Not the bushings in the back it’s more forward 


    • By two.colored.ls400
      Does anyone have a part number or a link where I could find a new fuel pump for my 2000 Ls400???
    • By Mattman615
      I have recently become the owner of a 2000 LX470. It’s the Gold edition, (Air-ride, sunroof, leather, AWD, V8, etc) This girl has had several timing belt replacements, and has been kept up very well. It has had several because the previous owner had it replaced once, and then the tensioner broke after replacement. He then had it changed out again. Any how, I’ve began to notice a lack of power and a straight up misfire on cold start only. This only happens when it is below Normal operating temp, and it is enough of a misfire that I can feel it stuttering, and it has a very strong hesitation to accelerate. It has new plugs, new fuel filter, And new air filter. It also has no stored trouble codes, and does not trigger a check engine light, as well as any other in dash monitors, and has not since this began around 3-4 months ago. Please give me a word of advice!! 
       
×
×
  • Create New...

Forums


News


Membership