Hi Everyone,
I have a 2000 rx300 and also had the P0330 code which came with bad performance, lots of knocking and not being able to go into overdrive after about 20 minutes of driving.
After reading the above "incredible" posts, I successfully replaced both Knock sensors and harness as well as the water transfer hose and spark plugs (because I was there).
I just wanted to contribute areas I thought were the most difficult and got stuck and had to go looking for a better tool etc.
The upper intake manifold was the biggest problem. There are three bolts at the back, so close to the firewall you can't see and will have a problem reaching with your finger let along a tool.
The first is a 14mm bolt on "your" far left side. It screws the Upper intake manifold to a bracket to stabilize it. The bracket has sides that make it difficult to reach the bolt. You can feel it with your finger however (if you work hard to get your hand back there). I couldn't use my standard socket wrench as it was to fat to clear that area. I had to go out and get a "gearWrench" pass-thru socket set. It has half the height and was able to do it. I had a 3/8 wrench. Maybe a 1/4 inch wrench would have been easier.
The second hardest was what appears to be a fuel line that bolts to the back of the Upper intake manifold to the far right (your right) close to the throttle body assembly. I think that was a 10mm. I used one of those 10mm open end wrench with a closed wratcheting end to do that (I guess you can tell that I'm a real grease monkey with these tool descriptions :).
The third was a ground wire that was behind the upper intake manifold. That can be last. I think also 10mm. When you get the two above off, you'll be able to move the upper intake manifold enough to simplify this one since the wire has a bit of play (and I mean a "bit").
Once you got the above off, front bolts, and the throttle body bolts, you could slide the Upper intake manifold to the left to move it. Keep in mind their are two bolts on the front two sides of the manifold that need removing after you take their nuts off. That requires a torx socket. Don't know the size, I improvised by forcing a 3/8 socket. Don't do that!
The other things I needed was a large enough hex socket for the front of the upper intake manifold (forgot the size). A torx socket for the lower intake manifold.
Getting the above off was the hardest part. I've seen posts of guys who felt they had to move the motors off it's mounts or getting through the engine firewall to get the upper intake manifold off. YOU DON'T HAVE TO DO THAT. After this, it was all pretty much connect the dots.
This is probably not recommended for safety reasons, but I didn't depressurize the fuel system and lost only about 8 to 16 oz of coolant during the process. If I had the right tools and did it before, I probably would have gotten done in 4 hours. Instead, because I had only one car and had to put it back together to go out and buy tools, it took me two days :(.
Oh... by the way. Don't let coolant get into the intakes. This can happen (1) when removing the lower intake manifold (hard to help this) and (2) removing the water transfer hose to replace (I recommend this, you don't want to have to go back in for anything in the near future so change what you can). If you do get coolant in their, use paper towels ad dab it all up. Some guy on some forum claimed to have engine problems after doing this job he attributes to letting to much coolant spill into the intakes.
Putting those bolts back on, good tools or not, won't be fun.
My car is now purring like a kitten!!
Hope this helps!!!
