Removing LS400 Driver Side Exhaust Manifold

[Lextreme II]

Great news! I talked to few Lexus Tech about removing LS400 exhaust manifold. They all stated that the passenger side would be easy, but the driver will require the whole engine to come down or out.

I examined this problem and JBrady was discouraged due to this complexity of replacing stock exhaust manifold to his custom made header. Due this fear, many potential buyer was turned off. However, its great news for JBrady and many others.

Here is what happened.
1. Remove the cats and the primary O2 sensor
2. Remove the Steering joint and along with rack & pinion
3. Loosen the engine mount bushings (both side)
4. Remove the driver side engine mount
5. Remove the exhaust nuts
6. Remove the exhaust studs (VERY IMPORTANT)
7. Use a jack to jack the engine up
8. The header will come right out.

Once the stock manifold came out, its time for my single turbo header to go in. So far its bolted on and tomorrow will be the big day for the completion of the diy project........

 

[JBrady]

David,

First, there is a difference in manifold/heat sheild design between the earlier cars and the 1998+ cars. I have speculated that the passenger side on GS400s and 1998-2000 LS400s and SC400s should be removable without pulling the engine. The drivers side is a MUCH harder task. This sounds the same as your earlier car but in fact is probably harder on my car due to the larger manifolds and heat shields that must be removed just to access the nuts and studs. Getting the shields off is in fact the first major problem.

Now, from your post, it sounds like you already removed BOTH your manifolds with the above procedure... correct? That is good and will apply to the early model LS400s. The early SC400s have had manifolds replaced by headers in Australia and a few cars here in the states. That tells me that those cars can have both manifolds removed without pulling the engine.

 

[Lextreme II]

I think the most important part is removing the studs. By removing the studs, you save about one full inch of space and that will allow the oem header to be extracted.

 

[13brett]

How do you remove the studs? Is there a special tool?