2003 Dodge Stratus Revs limited to 2500 RPM, code P0344-cra

Recently puchased car knowing the P0344 had been reset after crankshaft sensor and the camsensor had been replaced. Previous mechanic checked all grounds and said if new sensors don't fix it, it needs a new computer. Need to go to dealer and get new and have flashed. It did throw a code so instead of new, I bought a used ECU from same year and style car and code P0344 again appeared after 75 miles at same time it started rev limiting. Seems to eliminate the engine computer?

What car does is rev limits at about 2500rpm- intermittently, doesn't matter what gear I put it in- seems to run fine under 2500 RPM.

Car had rebuilt tranny installed at 50K, only other code shown in previous owners notes was Evap system related. He kept everything.

What can cause it to rev limit at 2500 RPM and throw the Crank sensor code?

Thanks