Hello, I have a 1991 Oldsmobile 88 Royal with the check engine lights on. I've been trying to get these two codes off for the longest.. Code 34 is the MAF sensor right ? I have replace about 3-5 off these from the junkyard and cleaned them with MAF sensor cleaner on my car and it'* still not fixing the code.. Its getting power from the wire ( 11.8V). I'm really lost on that one.. The other code is code 41 (Cam Sensor Circuit). I replace the Camshaft position sensor and that didn't work either.. I'm trying get the car to TDC for me to see if the cam Magnet (interrupter) is broken. How do I rotate the engine for me too see it? I took all the spark plugs out and removed the Water pump pulley..

This guide is great.. but I just don't really know how rotate the engine. Code 41: lost cam magnet in 3800

34 map sensor signal out of range, low (MAF sensor in a car with a MAF sensor and is for MAP sensor in a car with a MAP sensor.)

the pcm sees it as low so it could mean the wire is shorted to ground somewhere. look in the plug, the plug at the pcm, and anywhere alone the loom it goes near metal

as far as rotating the engine just get a socket to fit the big one on the pulley and a big wrench or breaker bar and turn it

My car has a MAF sensor. So, I'm taking it doesn't have both just one right? I will look for any metal parts around the wires when the sun comes up. When you say " socket to fit the big one on the pulley and a big wrench or breaker bar and turn it" do you mean the harmonic balancer bolt? If so, which way do I turn it and do the car need to be up for me to do it?

not really going to hurt anything if you turn it either way and from the top if you have room or if you dont from the bottom