I bought a 2007 Chevy Tahoe and the engine turned out to be bad. I had the vehicle In and out of the shop and on a second mechanic in the last year. I ordered a new engine for the Tahoe and now I'm getting misfires for the number 3 cylinder P003 code It also triggers the  Traction control light along with check engine light. I have run the vehicle with the scantool on it And are constantly replacing parts on the engine to figure out where the problem is. Currently today we replace sparkled twice replaced all coils replaced all wires we have replaced all fuel injectors we've replaced the computer for the vehicle. WE ARE pretty much at a loss to why we consistently get misfires on the number 3 cylinder we also get misfires on the other cylinders but it's very rare and only on start up. After about 10 seconds all the cylinders stop misfiring except for cylinder 3. The number 3 cylinder always misfires. THIS is Causing all sorts of questions Feel pression is correct intake manifold no leaks. I can't believe a brand new engine came and we have problems with it. The  Tahoe is a automatic transmission vehicle. I am open to any suggestions you may have

 Thanks Jeremy