greatwhiteshark

Went To look at drivers side plugs. Found completely shorted ignition coil wire. Was hanging together by sheathing only. separated about 4" back from distributer side connection. All wires are original 1993 sumtomo and looked fine except ignition coil wire. Looked only at 2 plugs on drivers side and they were not fouled gapped at .44 and seemed fine. Ordered original Lexus ignition coil wire. Note the wire reference number is the same for both sides of the engine but the drivers side is longer by about 2 incheds and needs to be if it is going on the drivers side. Anyway, new wire on and ran absolutely awesome... For a short time. Say, 5 miles. No doubt, that the drivers side ignition coil and ignition coil wire needed replaced. Caps and rotors are next in my mind. Any thoughts?

Update: New ignition coil still issues I noticed that only the drivers side cat is getting red hot. (bottom 40% of the cat). passengers side is not glowing or even a bit red. So I changed the drivers side igintiion coil. Good link here on how to change this one http://us.lexusownersclub.com/forums...howtopic=60609 The old one was cracked on the front face. Install of the new coil went smoothly except for one thing, I did break the locking tab on the main wire going into the center of it. perhaps this is my current issue?? perhpas not? I still have a noticable loss of power(not as bad as it was before the new coil but still noticable) and hot cat on drivers side. Not sure what to do next. Could this new cat have been runied so quickly? I have driven it a total of 25 miles on 4 occasions since I replaced the cats and 12 miles since replaced the failed ignition coil. I can get he car going 60-70 MPH but noticably slow. Could the cat be plugged and causing my low power issues? Could the lack of a locking tab on the main wire connecting to the front of the new ignition coil be the culprit? Any thougths? and thanks!

First of all thank you all for your input. I have been diagnosing this in the best way I know how with all of your input. OK here is where I am. Removed the resonator and replaced with a section of straight pipe. welded both ends. Resonator was clean and did not even look like it needed to be replaced. Still ran sluggish and rough. lower end of drivers side cat started to heat up and turn red again. passenger side similar but just barely red/pink also on the lower end of that cat. Ran diagnostics and no error codes. I am thinking I leave the exhaust alone now and focus on the engine. Not going to drive it again as i am afraid to going to ruin new cats. I will start with the spark plugs. seems to be running on 4 cylinders. Perhaps drivers side cylinders are not firing because of all the ATF that got dumped into the engine??? Aside from the spark plugs all I know to do is more research. Again, thank you all for sharing your experience here as I really miss driving my LS400.

It has been a while but wanted to provide an update. So here is what happened: The air control valve failed and the PS fluid (dex/merc) was sucked in to the engine. The PS fluid does not atomize(burn) well and consequently filled up the cats. the clogged cats restricted exhaust flow and overheated. The Ceramic honeycomb material was destroyed and some of it has likely found its way into the resonator. I have replaced the engine coolant temp sensor, both upstream O2 sensors, and both cats. Still ran rough and low power. Can drive it for more than a 10 minutes or cats start to heat up again. Mostly at the backside flange. I have driven it 7 miles since new cats and O2 sensors have been put on. Next I need to replace the resonator. I have 2 options. 1.) cut the resonator off and replace it with a straight pipe (about $80-100 parts and labor) or 2.) remove the entire center pipe section, Part # 17410-50021 http://www.lexuspartsnow.com/parts/l...410-50021.html (this is about $550 part and an hour of labor). The bottom line is that the 5 quarts of PS fluid caused a world of damage to the exhaust system. once I replace the resonator ill provide what i hope will be a final update for the group.

Thanks for all the input. Finally back in town and checked the cats. After a 15 minute drive with max speed of 40 mph while dark outside, I looked under at the cats and both red hot. Given the timing of all this i do think it was all of the ATF backing into the engine due to failed air control valve. Now need to order 2 new cats, jack it up and replace them. Not sure if i am going to plug the air control valve on the PS pump or replace it at this point. I am thinking of trying to remove the O2 sensor per code 28 and cleaning it before replacing it with a new one. Any thoughts on trying to clean the O2 sensor instead of replacing it? Ill post what i do and the results after the new cats are on. thanks to all of u for weighing in on this. Cant wait to get the new cats cause I miss my ls400.

OK i checked codes and here is the status. 25 - Air/Fuel ratio lean malfunction 28 - Main oxygen sensor signal (on right bank) so those are my codes and the car is loud rough and has 30% of its normal power. Again, I know i dumped a lot of ATF into the engine as a result of the failed air control valve but there is no ATF in the P/S system now after i realized that the ATF was going into the engine. I know i need to replace the air control valve on the P/S pump. If I replace the main oxygen sensor on the right bank I am assuming it makes sense to also do the left bank? I am also wondering if this will correct the lean air-fuel issue? I appreciate any input.

Thanks Curious B, the CEL (Check Engine Light?) if that is what CEL stands for is ON. it has been on since i had the issue with P/S and I have assmed it will be on until i finally replace the air control valve on the P/S pump. Yea no idle issues but power issues for sure. and car seems loud like leak in exhaust system. I just researched how to read the codes myself thanks to Lexls.com and am going to do this now. I have not driven the car for 3 days since this happened and i joined the forum. However, I will take it for a 10 minute drive and check out the cats as you suggested. More to come. And thanks for your time Curious B .

Dear CuriousB, Do u think the power loss and rough/loud exhaust is due to large amounts of ATF building up in the CAT's? Best

Thank Guru member, I think i am no on top of the air control valve. As i said in the end of my post, now i have a new problem and am trying to figure out why i suddenly have this big loss of power. I am guessing at at in the end of my post but looking to see if anyone has any experience with this. Thanks for your response. perhaps i should find a way to be more clear about the fact that i have figured out the ATF loss issue but now have a power loss issue. Again thanks.

First timer here. First thanks to this community for getting me this far. I learned alot just reading more posts than i can remember. I have a 94 ls400. Bought it 3 years ago with no issues. about 2 years ago the dash lights would flash on and off in the winter until the car got warm but i lived with it. 8 months ago power steering fluid started leaking. I was sure it was not leaking on the alternator but could not find the leak and could not afford to fix it. so i ran it with no fluid in the system for 6 months an developed popeye forearms. 3 weeks ago I find the leak in a hose running in front of the radiator and took it off and replaced the hose. Filled system, worked out the air and no leaks. Then started to notice the infamous smoke out the tail pipe and assumed just a coincidence that it started burning oil at the same time the PS was finely fixed. then started having to add ps fluid again but no leaks anywhere. I probably put in 5 quarts of dex/merc ATF in the system between replacing the hose to seal up the PS system and when I learned of the issue with a bad air control valve. This faulty was sending ATF back into the engine. So I stopped filling it. I ran the car 3 days a total of 45 miles without adding any fluid. Aside from working on my popeye forearms again to turn the steering wheel, all was well. By well i mean car was running smooth as silk just tuff to turn the wheel. This morning i started it up and it was rough feeling and sounding engine and exhaust especially from under the mid section of the car. very little power. hard to get it to go 45-50 mile an hour. Could all that ATF going into the engine be sitting in the catalytic converters and causing some exhaust flow or compression issues? any ideas before i put the the new air control valve on?