2004 chevy 2500HD Duramax. Transmission will not engage. Replaced sensor on side of transmission worked for a bit. I have been told that it needs to be a GM sensor?

SOURCE: Check Engine Light - O2 Sensor - bank 1 running lean

you should have three oxygen sensors on your car, one for each bank of three cylinders; should be towards the Y pipe on each exhaust manifold. Additionally you should have one on the exhaust pipe before the cadilitic converter.

SOURCE: 2000 chevy blazer, truck cranks

Does your battery go dead?

SOURCE: PO481 code Chevy IMPALA 2003

Looked it up in Chilton's, confirmed in http://www.obd-codes.com/trouble_codes/

P0481 Cooling Fan 2 Control Circuit Malfunction

Each fan will throw a different code. See 3 fans listed for your model. Here's a link for the wiring schematic: http://www.chiltonlibrary.com/content/images/WD/GM/014/WD_GM_014788.pdf


Best of luck.
Greg

SOURCE: 2000 chevy silverado z71 check engine light will not go off.

you have to know what the code is that your truck putting out your truck has 4 O2 sensors. the trucks computer is smart and the code will tell you witch one is bad but if you replace just one the next one on the same exhaust pipe will probley go bad so its safe to replace all four. the draw back to replaceing all of them is thay cost about 80 bucks for one ACDelco O2 sensor. It has to be done before it will pass Emissions. not a hard part to change about a 7/8 open end wrench will take it off. have fun.

SOURCE: where is knock sensor located on 2004 chevy 2500Hd

Under intake manifold on top of block,you need to remove intake to access sensors there are two of them you can't miss them when intake is off. After replacing sensors you need a new intake gasket.