Please help... I bought a MAF because my MAF was not reading at all on my mechanics diagnostic device which was throwing a p0101. So I knew to replace the sensor, I bought a new MAF online and installed it, Now I'm having a p0171 code come up; which I wasn't having an issue with before until I installed this new MAF sensor. So I think the sensor is defective because I wasn't throwing that code previously to the install. The code means fuel trim system lean (bank 1) Now there is numerous potential issues with this code that have been reported but the code hasn't come up until now. Please help me come up with a few ideas.
PS I just recently had a short block rebuild and I put the engine back together myself and I torqued everything to spec. I am also having an issue with the car reing out when it shifts into third gear. It seems to lose power at the time of rev. There is no smoke coming out of the back end. Thanks guys