2 months ago I had a 2003 Chevy Suburban that I wrecked. I purchased a 2003 Chevy Tahoe that did not have a engine. I had the engine taken out of my wrecked Suburban and put in the Tahoe. Once everything was completed. I started the Tahoe up, it has a misfire and is puttering when I drive it. I sometimes get a message on the dash engine power reduced, when this happens I have no power when I press the gas petal and the truck goes nowhere. I had a street mechanic look at it and was told I need a new ECM or computer. Can this be true? Please advise. Thanks

 

Yeap. Pull the old one out of you Burb if you can. Might have messed up something in the crossover as well. Put ii on an an OBD II code reader and post the results. A street mechanic who only owns a cheap OBD reader, if that, is NOT who you need to have this done properly

 

Should I order a new programmed ECM by vin number for the suburban or the Tahoe?

 

Possibly, if the original does not work. There are techs who may be able to reprogram the ECU for you.