I have an '03 XLS that has been showing odd symptoms. A week ago I had multiple codes (P0456, P0110, P0442, P0100). I found that the intake hoses between the air filter and the throttle bodies were badly cracked. While they were out I de-gunked the throttle bodies and shot a bunch of carb cleaner into the idle control valve port. Once the intake tubes were replaced I reset the codes and the car ran great for a for several days. The CEL came on again but this time only gave a P0442 code. I know the general fixes for that code but the car has intermittently been difficult to start, as in, it starts just fine but won't idle and dies immediately unless you keep your foot on the throttle for a couple of minutes. After a bit of sitting at 2000 rpms it settles down and idles without help. My question is: could the P0442 explain this? This seems extreme for a code that says "small leak". Many thanks.