I have a sc400 Lexus. Have no Idea where to buy repair manual or parts. Read below and please help.

I am supposed to be on crutches, so I am doing what work I can get to. This car started cranking up idled up high again, with the check engine light on and it won't idle down anymore, like it was doing in the beginning. Turning it off and back on doesn't work anymore. If you drive, you have no power, you use a crap load of gas, and maybe if lucky, it idles down, chugs awhile and then starts running perfect and the A/C starts cooling again, or you stop at the store and come back out and it starts up and runs perfect, just like before. I managed to clean out the EGR Valve, and blew out the filter and all on the EGR vacuum modulator. I removed EGR from the intake manifold, and the hole on the manifold was almost 75% clogged with carbon. I cleaned it out real good, except I am not sure how far up in there that hole goes. I can make the EGR diaphram move by applying vacuum on the hose. I removed the neg on the battery, and the fuse to the EFI for over 30 minutes, but the car started up the same way with the engine light staying on. I have tried to jump the terminals as per your March 19 post, and I can not get that CEL light to flash at all. I am about ready to think I should buy new O2 sensors as when it did flash, those were two of the codes 21 and 28. The email you sent, where are those terminals located? And where is the ECU, under the glove box or somewhere? It is so difficult for me, with a bad knee, and the muggy weather, I get sick trying to work on it, probably not thinking clearly and getting frustrated. But trying like hell to keep it together. I put a zip tie behind the steering column tilt gear so the steering wheel would go up and down, so I could get the instrument cluster out. I had so many bulbs out, at night I couldn't see the gas gauge. Temporary solution I rearranged some bulbs to light up most of the cluster until later, still no speedometer yet, I want to get the thing running right first. But I am thinking, what if all these problems are all related and are in the wiring and ECU like we have discussed? Then I will have my work cut out for me and it is going to be tough and bulbs will be the least of my worries

So, I think we should go back to the August 30th reply from you. Send me the wiring diagrams, and procedures to check the MIL and let me see if I can find out why the paper clip won't flash any codes. When the car runs right the O/D light flashes all the time even with the button pushed in on the shift knob. But when the car runs slugglish, that light goes out completely. I have tried several times to make those codes flash but the light just stays on and nothing ever flashes

Just went on about a 30 mile trip, and almost home, the car cleared up and went to running ok. I ran in the house and grabbed the paper clip, and viola. Code 21, code 28, code 71 on the Check engine light. And the O/D flashed a code 42. So Looks I am going to need those maybe those O2 sensors, something is STILL wrong in the EGR Circuit, and this time it pull up a Speed Sensor Circuit issue. I am getting excited cause I have never gotten any of this before.