2001 Pathfinder lack of high RPM and P1140, P1145 errors

[RSabre]

I have a 2001 LE automatic, the biggest problem I am having now is when accelerating fast or climbing a hill I can't rev the engine past 3,500 or sometimes 4,000 rpms. This started about six months ago. I changed the plugs, air filter, fuel filter and checked the catalitic converters as it seems to be either lacking gas on accelaration or too much back pressure?? I can set and just rev the engine without any problem and it doesn't miss. I burn regular gas in it but have never had problems.

The SES lamp came on about 2 years ago found out it was a P1140, tried it on both sides but no help, took to Nissan and the mechanic couldn't find the problem after 2 hours, thought it may be an wire open but I have reseated all wiring connections with no positive results.
Modified by RSabre at 11:13 AM 1/30/2009