94 ls400 glowing exhaust lazy throttle
12-06-22, 05:10 PM
#1
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94 ls400 glowing exhaust lazy throttle
First timer here. Thankful for any help
120,000 miles on the car. It starts and idles. Idle is a little bit low If you go slow with the throttle you can get it up to 3000 RPMs after running for 10 minutes both sides of the exhaust are glowing red. I replace the ECU, I replace the mass airflow sensor. I tested for fuel flow and also for fuel pressure. I’ve unplugged each coil one at a time with a noticeable difference I’ve checked the timing marks. I’ve sprayed everywhere looking for vacuum leaks. No codes. I’ve also remove the exhaust and it runs the same.
120,000 miles on the car. It starts and idles. Idle is a little bit low If you go slow with the throttle you can get it up to 3000 RPMs after running for 10 minutes both sides of the exhaust are glowing red. I replace the ECU, I replace the mass airflow sensor. I tested for fuel flow and also for fuel pressure. I’ve unplugged each coil one at a time with a noticeable difference I’ve checked the timing marks. I’ve sprayed everywhere looking for vacuum leaks. No codes. I’ve also remove the exhaust and it runs the same.
12-07-22, 09:23 AM
#2
Intermediate
First timer here. Thankful for any help
120,000 miles on the car. It starts and idles. Idle is a little bit low If you go slow with the throttle you can get it up to 3000 RPMs after running for 10 minutes both sides of the exhaust are glowing red. I replace the ECU, I replace the mass airflow sensor. I tested for fuel flow and also for fuel pressure. I’ve unplugged each coil one at a time with a noticeable difference I’ve checked the timing marks. I’ve sprayed everywhere looking for vacuum leaks. No codes. I’ve also remove the exhaust and it runs the same.
120,000 miles on the car. It starts and idles. Idle is a little bit low If you go slow with the throttle you can get it up to 3000 RPMs after running for 10 minutes both sides of the exhaust are glowing red. I replace the ECU, I replace the mass airflow sensor. I tested for fuel flow and also for fuel pressure. I’ve unplugged each coil one at a time with a noticeable difference I’ve checked the timing marks. I’ve sprayed everywhere looking for vacuum leaks. No codes. I’ve also remove the exhaust and it runs the same.
12-07-22, 01:58 PM
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I’ve unplugged each ignition coil, one at a time and noticed skipping, so I believe the coils are good. It’s glowing on both exhaust manifolds, so if it were an injector dumping wouldn’t it be one side? O2 sensors are next on my radar
12-07-22, 03:12 PM
#4
Intermediate
I assumed the cats were glowing when you said exhaust. Glowing exhaust manifolds are not good and need to be addressed before a fire starts lol
12-07-22, 05:03 PM
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Are the upstream O2 sensors original? That should throw a code but i would check them with a multimeter at the least. Its worth it to replace them if they are 20+ years old as well, especially the upstream sensors which effect your A/F ratio.
I assumed the cats were glowing when you said exhaust. Glowing exhaust manifolds are not good and need to be addressed before a fire starts lol
I assumed the cats were glowing when you said exhaust. Glowing exhaust manifolds are not good and need to be addressed before a fire starts lol
when you say O2 sensors up stream do mean closest to engine?
12-07-22, 05:40 PM
#6
Lexus Fanatic
Disconnect O2 sensors see if anything changes. If no, then disconnect injectors one at a time.
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12-08-22, 05:13 AM
#8
Moderator
As long as the ECU is working properly, it prevents the glowing completely. I suspect that the replaced ECU is not functioning well or something is disturbing it to work right. If no error codes were available, I'd simply check the ripple level first as is explained in the FAQ. I worry that the replaced ECU is not properly fixed. I'd say that it's only the company Denso that can fix/repair it. Many private rebuilders are not doing the fix/repair as Denso is doing.
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