# still not performing at maximum



## ElmerC (Jan 30, 2020)

Okay so my Altima SER had a cracked head gasket for about a year, and about a month ago i was driving down the road and a car was tailgating me so i stepped on it, and i redlined the engine im pretty sure, i didnt quite noitce but all i hear was my engine like blow. So about a week ago i got a new engine installed, it was a 2006 3.5 Maxima engine and my mechanic had to use like manifold and block from the SER engine so it can fit better. My car is preforming better now, finally no burnt oil smoke coming out the exhaust. The car still is struggling, when i step on it doesn't pass 4200 RPM and i hear a lot on engine noise when i drive/step on it. Buddy of mine says it might be the cats, but need yalls opinion.


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## rogoman (Dec 16, 2004)

When your mechanic replaced the engine, he should have used all the external accessories from the old engine like the intake/exhaust manifolds *along with the old sensors* and the old fuel injectors and rail. The marginal performance issue may be caused by a bad sensor(s) or bad fuel injector(s) that were on the new engine.


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