jqzhang

I understand what you're saying and I agree. Now I'm going to the full length to have it done, taking your advice. I did have the link that you sent me, which is my guide for the project. I also have the detailed description from TIS (Tech. Information System) so I should be OK. Thank you very much for all your help.

Yes. It makes sense. I'll probably do it during the holidays. One more question for the 1990 one: the one with water pump problem. I am in the process of ripping it apart but one thing surprised me. The timing belt looks quite new. It must be replaced not too long ago (but not me). I guess they changed the belt not the water pump. My question is, can I replace the pump and leave the belt alone? It looks like I have to loose the belt before I have access to the pump. Thanks again.

No, my CEL is not lit yet since I stoppd driving the car after I heard the noise. If I kept driving, it would light up for sure. I agree with you about the re-routing stuff because you cannot beat the design of the car. I have a 96 Lancruiser too. There is slightly leaking in both converters because of rust. I tried welding using flux core wire (MIG welding machine). It is not working well: either burning the steel through or not enough penetration. Someone suggested using gas welding. I'm not sure. Any ideas about that? Of course, for the EGR pipe, I'd probably replace it with a new pipe. Thanks in advance.

Thanks for the quick return, and the tips too. They are going to be helpful. I did not know so many Toyota and Lexus models use the same water pump. Good to know. I read some posts saying that if the the leak is at the EGR pipe, the upper end of the pipe can be blocked or capped. The emission won't be affected so the car can still pass inspection no problem. Sounds hard to believe. What if the CheckEngine light might come on because the oxygen sensors might sense the change first. What would you think? Thanks again.

Hi, Hope you all is well. But bad luck for me. The 1995 one has a broken exhaust, probably EGR pipe but not sure since it's hard to detect. Any suggestions? For the 1991 LS400, coolant is leaking slightly from the bottom of crankshaft pulley. I am afraid the water pump is gone. Any someone confirm that? Because I don't want to go through the pain of replacing water pump, probably timing belt too, but end up with something that doesn't take me that far. I have a used part of water pump taken out from a 95 SC400, which can probably fit my LS400 of 91. If not, have to get a new one. Greatly appreciate it! jqz.

One more question. I changed the plugs about a couple of years ago using Bosch. I heard something negative about those plugs (I was trying to get some NGKs but they were out of stock). So what's so bad about Bosch plugs? Thanks in advance.

You probably right about it. But my question still is if replacement of the converters can make the exhaust smell better. I don't think they are clogged because there is no hesitation as long as the engine warmed up. Thanks.

Thanks Jaswood for the valuble tips. I'll certainly follow what you said and check it out. Have a good one.

Hi, Hope all is well with you guys. My 1991 LS400 cannot pass inspection. I bought a oxy. sensor from Ebay and replaced the old one since I had a trouble code indicating the sensor on the right bank had failed. It did not work: check engine light still on; another code tells me the fuel mixture is lean. I suspect the converters be gone because the exhaust really smells. I'm planning to buy a universal one that is cheap. In case it did not work, I'd only lose about $50. Would you think a bad oxy. sensor can cause bad smell of exhaust? I doubt it. I read some reviews. It looks like people change converters just to quiet down the noise instead of improving the emission. I'm confused. Noises come from bad exhaust pipes or mufflers, not converters. What would you think? BTW, the car has about 159K miles on it; newly rebuilt starter; 2 year old of radiator; another symptom: occasional missing when engine is hot, not very frequent; it may have something to do with lean mixture of the fuel, maybe converters. Thanks in advance.

Thanks. But I clean the throttle body and it did not solve the problem. I have to try something else. Thanks again.

Hi, I have a 1991 Lexus Ls400 with a mileage of over 150k. The problem is the engine misfire especially when it's hot, I mean after warming up. 1) the radiator is 2 or 3 years old, copper or brass; 2) newly changed thermostate valve; 3) newly rebuilt starter (pain in the neck job); 4) Check Engine light has been on for a couple of years: main oxy sensor at the right bank, replaced but the light won't go away; 5) converters are sort very old but doubt they will cause missing; 6) plugs and ignition wires 2 years old; 7) one of the ignition modules a few months old; 8) when doing 40M to 50M per hour, the car starts jerky. It feels like a tranny lock-up failure but at other speed range, it would be fine. Any suggestions? A mechanic told me it's sort of common for early model of LS400. My 95 LS400 behaves similar but not so obvious. When the engine misfires, it will get worse. Thanks in advance John Z.

It's because so many of us have dealt with the exact same problem on our gen 1 LS400's. Sometimes I wake up at night screeming "IT'S THE LEFT TRUNK HINGE WIRES!!! THERE'RE BROKEN!!! AHHHHHH!!!". The remote for opening the trunk is not working for a while. Does that have anything to do with the broken wires? If it does, how come it's still not working after the wires are fixed? thanks in advance.

It's because so many of us have dealt with the exact same problem on our gen 1 LS400's. Sometimes I wake up at night screeming "IT'S THE LEFT TRUNK HINGE WIRES!!! THERE'RE BROKEN!!! AHHHHHH!!!".

Python & fsuguy, I cannot help saying that you guys are incredible. Really, I mean it. Following you guys' comments, I have it fixed, even not completely. I don't know why but mine is slightly diff. from what you mentioned. I saw a picture that CUMan posted (I guess). It was a 12 pin female socket so you have to find out which wire is really broken. Mine is easier. About 5 or 6 wires covered by a black plastic box with the size of a small Bic lighter (too bad I don't have my camera handy). The broken wires are just right there for you to pick: a grey and a white. I said 'not completely' since the remote for trunk opening is still not working. I suspect there be some more broken wires that I haven't found yet. Don't you agree? But at least the weird response of tranny is gone and the shift-lights on the dashboard come back normal, thanks to you guys. I was curious, very much. How the heck you guys found out about the trunk wiring harness was the culprit? I believe most of the dealership won't be able to pin-point the problems either. They may go through the routine that I did: check the trouble code first. Then I would change the TPS for nothing, so would the dealership. Again, you guys are great! I really appreciate your help.

Thanks Python. I checked the trouble code. It's 41: TPS problem (probably ECU, but I'll take my chance of assuming ECU's OK). I guess I have both: the trunk harness and TPS. Don't you think so? Can I have some details about how to fix the trunk harness? Thanks again Python!